eccentric 
 noun
 A disk or wheel with its axis off centre, giving a reciprocating motion.
 One who does not behave like others.
 (slang) a kook
adjective
 Not at or in the centre.
 Not perfectly circular
 an eccentric or elliptical orbit
 Having a different center.
 Deviating from the norm; behaving unexpectedly or differently.
 "He has become really eccentric over the years."
 (physiology) (of a motion) against or in the opposite direction of contraction of a muscle. (E.g. flexion of the lower arm while flexing the tricep; opening of the jaw while flexing the masseter). (Antonym: Concentric)


eigenfunction 
 noun  (math) A function φ such that, for a generic linear operator D (e.g. differential one), Dφ = λφ where λ is an eigenvalue of the operator.
 (quantum) Any eigenfunction of the Hamiltonian operator, representing a quantum state whose energy level is given by the corresponding eigenvalue.

eigenvalue 
 noun
 (linearalg) The change in magnitude of a vector that is not rotated under a given linear transformation; formally, a scalar <math>\lambda</math> such that, for a particular matrix <math>A</math>, <math>A x = \lambda x</math> for some nonzero vector <math>x</math>, an eigenvector of the matrix; thus, a value of <math>\lambda</math> such that <math>\mathrm{det}(A  \lambda I) = 0</math> for a given square matrix <math>A</math>, where <math>I</math> is the identity matrix and <math>\mathrm{det}</math> is the determinant operator.

eigenvector 
 noun (plural eigenvectors)
 (linearalg) A vector that is not rotated under a given linear transformation; a left eigenvector, left or right eigenvector depending on context.
 (context, physics, engineering) A right eigenvector; a nonzero vector <math>x</math> such that, for a particular matrix <math>A</math>, <math>A x = \lambda x</math> for some scalar <math>\lambda</math> which is its eigenvalue and an eigenvalue of the matrix.

element 
 noun
 (chemistry) Any one of the simplest chemical substances that cannot be decomposed in a chemical reaction or by any chemical means and made up of atoms all having the same number of protons.
 One of the four basic building blocks of matter in theories of ancient philosophers and alchemists: water, earth, fire, and air.
 Something small.
 an of doubt
 A place or state of being that an individual or object is better suited towards.
 be in one's own
 A required aspect or component of a cause of action. A deed is regarded a violation of law only if each element can be proved.
 (set theory) One of the objects in a set.
 A group of people within a larger group having a particular common characteristic.
 You sometimes find the hooligan at football matches.
 A short form of heating element, a component in electrical equipment, often in the form of a coil, having a high resistance, thereby generating heat when a current is passed through it.
 The in this electric kettle can heat the water in under a minute.

elementary function 
 noun (wikipedia, elementary function (differential algebra))
 (mathematics) Any function that is composed of algebraic functions, trigonometric functions, exponential functions and/or logarithmic functions, combined using addition, subtraction, multiplication and/or division

eliminate 
 verb (eliminat, ing)
 (transitive) To completely destroy (something) so that it no longer exists.
 (slang) To kill (a person or animal).

elimination 
 noun  The act of eliminating, expelling or throwing off
 the act of discharging or excreting waste products or foreign substances through the various emunctories.
 Act of causing a quantity to disappear from an equation; especially, in the operation of deducing from several equations containing several unknown quantities a less number of equations containing a less number of unknown quantities.
 The act of obtaining by separation, or as the result of eliminating; deduction. See Eliminate, 4.

ellipse 
 noun
 (geometry) A closed curve, the locus of a point such that the sum of the distances from that point to two other fixed points (called the focus, foci of the ellipse) is constant; equivalently, the conic section that is the intersection of a cone with a plane that does not intersect the base of the cone.
verb (ellips, ed)
 (context, grammar) To remove from a phrase a word which is grammatically needed, but which is clearly understood without having to be stated.
 In the exchange: (A.Would you like to go out?, B.I'd love to), the ellipsed words are <u>go out.</u>

ellipsograph 
 noun
 A mechanical instrument used to trace out an ellipse. Applied to draw, cut, etc mathematically correct ellipses (rather than general ovals).

ellipsoid 
 noun  (mathematics) a surface, all of whose cross sections are elliptic or circular (includes the sphere)
adjective  (mathematics) of or pertaining to an ellipse; ellipsoidal

ellipsoidal 
 adjective  (mathematics) of or pertaining to an ellipse or an ellipsoid

elliptic function 
 noun  (mathematics) Any function of a complex variable which is periodic in two directions

embed 
 verb (embed, d, ing)
 To lay as in a bed; to lay in surrounding matter; to bed; as, to embed a thing in clay, mortar, or sand.

embedding 
 noun  (mathematics) A map which maps a subspace (smaller structure) to the whole space (larger structure).
verb
 (present participle of, embed)

empty 
 noun (empt, ies)
 A bottle previously containing some liquid, especially a drink, and that is now empty.
 Put the empties out to be recycled.
verb (empties, emptying, emptied)
 (transitive) (ergative) to make empty; to void; to remove the contents of
adjective (empti, er)
 devoid of content

endomorphism 
 noun  (geology) The assimilation of surrounding rock by an intrusive igneous rock
 (mathematics) A homomorphism that maps a system to itself

enneagon 
 noun
 (geometry) a polygon with nine sides; a nonagon.

entire function 
 noun  (mathematics) Any function of a complex variable that is holomorphic throughout the complex plane

envelope 
 noun (plural envelopes)
 A paper or cardboard wrapper used to enclose and small, flat items, especially letters, for mailing.
 Something that envelops; a wrapping
 A bag containing the lifting gas of a balloon or airship.
 (geometry) A mathematical curve, surface, or higherdimensional object that is the tangent to a given family of lines, curves, surfaces, or higherdimensional objects.
 (electronics) A curve that bounds another curve or set of curves, as the modulation envelope of an amplitudemodulated carrier wave in electronics.
 (music) The shape of a sound, which may be controlled by a synthesizer or sampler.
 (computing) The information used for routing an email that is transmitted with the email but not part of its contents.
 (biology) An enclosing structure or cover, such as a membrane.
 (engineering) The set of limitations within which a technological system can perform safely and effectively.

epicycle 
 noun  (astronomy) (in Ptolemaic cosmology) a small circle, moving around the circumference of a larger circle having the earth at its centre; the supposed orbit of a planet
 (mathematics) any circle whose circumference rolls around that of another circle, thus creating a hypocycloid or epicycloid

epicycloid 
 noun (plural epicycloids)
 (geometry) The locus of a point on the circumference of a circle that rolls without slipping on the circumference of another circle.

epsilon 
 noun
 The name for the fifth letter of the Greek alphabet, Îµ or Î�, preceded by delta (Î�, Î´) and followed by zeta (Î�, Î¶).
 (context, phonetics) In International Phonetic Alphabet, IPA, the phonetic symbol that represents the w:openmid front unrounded vowel, openmid front unrounded vowel. Represented in SAMPA as E.
 (context, mathematics) An arbitrarily small quantity.
 (context, computing, colloquial) A negligible effect.
 Yes, we have to convert all the symbol names to upper case at startup, but that"s .

equality 
 noun (equalities, )
 (uncountable) The fact of being equal.
 (uncountable) (mathematics) The fact of being equal, of having the same value.
 (uncountable) The equal treatment of people irrespective of social or cultural differences.

equal sign 
 noun (plural equal signs)
 A symbol ( = ) used in mathematics to indicate that two values are the same, and elsewhere in various other ways, such as (formerly) to separate the signature from the content of a telegram.
<!NOTE: "equal sign" is not a computing term. In computing, = represents either the assignment operator or the equality operator, depending on the language. It is never properly called "the equal(s) sign".
Note also that other USES of this symbol do not provide other SENSES of the term, as the symbol remains the same one.>

equation 
 noun
 (math) An assertion that two expressions are equal, expressed by writing the two expressions separated by an equal sign; from which one is to determine a particular quantity.

equiangular 
 adjective  (geometry) Referring to a polygon all of whose interior angles are equal. This is not necessarily a regular polygon, since that would also be equilateral; a rectangle is equiangular but not equilateral, unless it is a square.
Translations

equidistant 
 adjective
 occupying a position midway between two ends or sides
 occupying a position that is an equal distance between several points. Note that in a onedimensional space this position can be identified with two points, in a twodimensional space with three points (not on the same straight line), and in a threedimensional space with four points (not in the same plane).
 (cartography) Describing a map projection that preserves scale. No map can show scale correctly throughout the entire map but some can show true scale between one or two points and every point or along every meridian and these are referred to as equidistant.

equilateral 
 adjective  (geometry): Referring to a polygon all of whose sides are of equal length. Not necessarily a regular polygon since the angles can still differ (a regular polygon would also be equiangular).

equivalence class 
 noun (plural equivalence classes)
 (settheory) Any one of the subsets into which an equivalence relation partitions a set, each of these subsets containing all the elements of the set that are equivalent under the equivalence relation.

equivalence relation 
 noun (plural equivalence relations)
 (settheory) A binary relation that is reflexive, symmetric and transitive.

equivalent 
 noun
 anything that is virtually equal to another
 (chemistry) an equivalent weight
adjective
 similar or identical in value, meaning or effect; virtually equal
 (mathematics) of two sets, having a onetoone relationship
 (mathematics) relating to the corresponding elements of an equivalence relation
 (chemistry) having the equal ability to combine
 (cartography) of a map, equalarea

erect 
 verb (erects, erecting, erected)
 (transitive) To put up by the fitting together of materials or parts.
 (transitive) To cause to stand up or out.
adjective
 upright, Upright; vertical or reaching broadly upwards.
 rigid, Rigid, firm; standing out perpendicularly.

error 
 noun  (countable) A mistake.
 (mathematics) The difference between a measured or calculated value and a true one.
 (baseball, countable) A play which is scored as having been made incorrectly.
 (context, appellate, _, law, uncountable) One or more mistakes in a trial that could be grounds for review of the judgement.
verb
 (nonstandard) To make a mistake; to result in an error.
 1993 December, Arie Kaufman (editor), Rendering, Visualization, and Rasterization Hardware, SpringerVerlag New York LLC
 :Pixels which are mathematically outside of a triangle, but which are included for antialiasing purposes can be generated with colour and depth information outside of the valid range. The ADE should identify these cases and clamp the output to the minimum or maximum value depending on the direction it has errored in.
 2000 December, Randy W. Kamphaus, Clinical Assessment of Child And Adolescent Intelligence, Allyn & Bacon
 :By doing so examiners are erroring in the direction of drawing hypotheses based on greater evidence of reliability and validity.
 2001 November, Daniel D. Dancer, Shards and Circles: Artistic Adventures in Spirit and Ecology, Trafford Publishing
 :Error is not just permitted by diversity; it is what permits diversity.... The beetle had "errored" beautifully
 2002 May, Sylvain Beauregard, Passion Celine Dion the Book: The Ultimate Guide for the Fan!, Trafford Publishing
 :Many other celebrities errored in the political comments area...

Euclidean 
 adjective
 Of or relating to w:Euclid, Euclid's w:Euclid's Elements, Elements, especially to Euclidean geometry.

Euclidean algorithm 
 noun  (algebra) a method based on the division algorithm for finding the greatest common divisor (gcd) of two given integers.

Euclidean geometry 
 noun (uncountable)
 (geometry) The familiar geometry of the real world, based on the postulate that through any two points there is exactly one straight line.

Euclidean group 
 noun  (mathematics) the set of rigid motions that are also affine transformations

Euclidean space 
 noun
 Ordinary twodimensional, two or threedimensional space, characterised by an infinite extent along each dimension and a constant distance between any pair of parallel lines.
 (mathematics) any vector space on which a realvalued inner product is defined.

evaluate 
 verb (evaluat, ing)
 to draw conclusions from by examine, examining
 It will take several weeks to the material gathered in the survey.
 (math)to compute an expression
 Evaluate this polynomial

even 
 noun
 (context, archaic, or, poetic) evening, Evening.
verb
 To make flat and level.
 We need to even this playing field; the west goal is too low.
adjective
 Flat and level.
 Clear out those rocks. The surface must be even.
 Without great variation.
 Despite her fear, she spoke in an even voice.
 Equal in proportion, quantity, size etc.
 The distribution of food must be even.
 (arithmetic) (no comparative or superlative) Leaving no remainder when divided by 2.
 Four, fourteen and forty are even numbers.
adverb (notcomp)
 (context, archaic or rhetorical) exactly, just, fully
 I fulfilled my instructions as I had promised.
 You are leaving tonight? — Even so.
 Implying an extreme example in the case mentioned, as compared to the implied reality
 Even a blind squirrel finds an acorn sometimes.
 Did you make it through the front door?
 That was before I was born.
 Emphasising a comparative
 I was strong before; but now I am stronger.

evolution 
 noun
 (context, general) A gradual process of development, formation, or growth, esp. one leading to a more advanced or complex form.
 (biology) The change in the genetic composition of a population over successive generations.
 (mathematics) The extraction of a root from a quantity.
 (military) One of a series of ordered movements.

exact 
 verb
 (transitive) Demand and enforce the payment or performance of.
 (transitive) Make desirable or necessary.
 (transitive) Extract forcibly.
 to revenge
adjective
 Precisely agreeing with a standard, a fact, or the truth; perfectly conforming; neither exceeding nor falling short in any respect.
 The clock keeps time.
 He paid the debt.
 an copy of a letter
 accounts
 Habitually careful to agree with a standard, a rule, or a promise; accurate; methodical; punctual
 a man in observing an appointment
 In my doings I was .
 Precisely or definitely conceived or stated; strict.

example 
 noun
 Something that is representative of all such things in a group.
 Something that serves to explain or illustrate a rule.
 Something that serves as a pattern of behaviour to be imitated (a good example) or not to be imitated (a bad example).
 "Learn from me, if not by my precepts, then at least by my example, how dangerous is the acquirement of knowledge"  Mary Shelley, Frankenstein
 A person punished as a warning to others.
 A parallel or closely similar case, especially when serving as a precedent or model.
 An instance (as a problem to be solved) serving to illustrate the rule or precept or to act as an exercise in the application of the rule.

exp. 
 abbreviation  experience
 expiration

explicit 
 adjective  very specific, clear, or detailed
 I gave instructions for him to stay here, but he followed me, anyway.
 containing material (e.g. language or film footage) that might be deemed offensive or graphic
 The film had several scenes including language and sex.

exponent 
 noun
 One who expounds, represents or advocates
 (mathematics) The power to which a number, symbol or expression is to be raised. As in the "3" in x^{3}.

exponential function 
 noun  (mathematics) Any function in which an independent variable is in the form of an exponent; they are the inverse functions of logarithms

exponentiation 
 noun
 (context, mathematics, arithmetic, uncountable) The process of calculating a power by multiplying together a number of equal factors, where the exponent specifies the number of factors to multiply.
 In 5^{4}, the factors are all 5, the power is 4 and gives the result 625.
 (context, mathematics, arithmetic, countable) A mathematical problem involving exponentiation.

expression 
 noun
 A particular way of phrase, phrasing an idea.
 A colloquialism or idiom.
 The "break a leg!" should not be taken literally.
 A facial appearance usually associated with an emotion.
 (math) A set of symbols denoting values and operations performed on them.
 (biology) The process of translating a gene into a protein.
 (context, programming) A piece of code in a highlevel language that returns a value.
 The process of expressing milk

extension 
 noun
 The act of extending or the state of being extended; a stretching out; enlargement in breadth or continuation of length; increase; augmentation; expansion.
 That property of a body by which it occupies a portion of space (or time, e.g. "spatiotemporal extension")
 Capacity of a concept or general term to include a greater or smaller number of objects;  correlative of intension. Synonymous with denotation.
 A written engagement on the part of a creditor, allowing a debtor further time to pay a debt.
 The operation of stretching a broken bone so as to bring the fragments into the same straight line.
 (weightlifting) An exercise in which an arm or leg is straightened against resistance.
 (fencing) A simple offensive action, consisting of extending the weapon arm forward.
 A numerical code used to specify a specific telephone in a telecommunication network.

exterior 
 noun
 the outside parts or surface of something
 It was written on the exterior
 foreign lands
 She is our new minister of the exterior
adjective
 relating to the outside parts or surface of something
 being from outside a country, foreign
 outdoor

exterior angle 
 noun
 (context, Geometry) An angle formed between one side of a polygon and an extension of an adjacent side.


extremum 
 noun (pl=extrema, pl2=extremums)
 (mathematics) a point, or value, which is a maximum or a minimum
