R 

noun The eighteenth letter of the Appendix:Roman script, English alphabet, preceded by Q and followed by S.
abbreviation
(context, US politics) Republican

(film certification) restricted
 reverse

right (as opposed to left)

(context, handbells) ring

(context, baseball, cricket) The statistic reporting the number of runs scored by a player
 Thursday
 
r. 

abbreviation
 rare

rad 

noun

(metrology) A nonSI unit of absorbed dose of radiation, equal to 0.01 gray.
adjective

(slang) excellent, short for radical

radial 

noun
 a radial tire / radial tyre
adjective
 arranged like rays that radiate from, or converge to a common centre
 moving along a radius

(anatomy) of, or relating to the radius bone

radian 

noun

(geometry) In the International System of Units, the derived unit of plane angular measure of angle equal to the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle. Symbol: rad

radical axis 

noun
(mathematics) a radical line

radicand 

noun

(mathematics) The number or expression whose square root or other root is being considered; e.g. The 3 in <math>\sqrtn{3}</math>

radii 

noun

(plural of, radius)

radiosymmetrical 

adjective
 having radial symmetry

radius 

noun (radii, pl2=radiuses)

(anatomy) The long bone in the forearm, on the side of the thumb.

(geometry) A line segment between any point on the circumference of a circle and its center/centre.

(geometry) The length of this line segment.

radix 

noun
 A primitive word, from which spring other words.

range 

noun
 Line or series of mountains.
 Large fuelburning stove.

Selection, array. Eg: A range of cars.
 Area used for shooting, artillery, etc.
 An area of open, often unfenced, grazing land.

(mathematics) The set of values (points) which a function can obtain.

(statistics) The length of the smallest interval which contains all the data. It is calculated by subtracting the smallest observations from the greatest.
 The distance to a target, or to the subject of discussion.
We could see the ship at a range of five miles.

(sports) (baseball) The defensive area that a player can cover.
Jones has good for a big man.

(music) Compass  The scale of all the tones a voice or an instrument can produce.

(ecology) The geographical area or zone where a species is normally naturally found.
verb (ranges, ranging, ranged)

(intransitive) (followed by over) To travel over (an area, etc) with a particular purpose.

(intransitive) (mathematics, computing; followed by over) Of a variable, to be able to take any of the values in a specified range.
The variable x ranges over all real values from 0 to 10.

(transitive) classify

ratio 

noun
 A number representing a comparison between two things.
 A judicial decision.

rational function 

noun
(mathematics) Any function whose value can be expressed as the quotient of two polynomials (except division by zero)

rationalize 

verb (rationaliz, ing)
 to make something rational
 to justify an immoral act, or illogical behaviour

(mathematics) to remove radicals , without changing the value of an expression or the roots of an equation
 to structure something along modern, efficient and systematic lines, or according to scientific principles

rational number 

noun

(mathematics) A real number that can be expressed as a ratio of two integers.

real 

noun

A commodity; see reality.

(grammar) One of the three genders that the common gender can be separated into in the Scandinavian languages.
adjective (er, more)
 That can be characterized as a confirmation of truth.
 That has physical existence.
No one has ever seen a real unicorn because they don't exist.

(economics) Having been adjusted to remove the effects of inflation; contrasted with nominal.
real consumption
real GNP

(economics) Relating to the result of the actions of rational agents; relating to neoclassical economic models as opposed to Keynesian models.

(mathematics) Relating to numbers with a onetoone correspondence to the points on a line.
 Relating to immovable tangible property.
real estate
real property
 That is an exemplary or pungent instance of a class or type.
a real problem
a real hero
 Genuine, not faked.
real tears
 Genuine, not artificial.
real leather

(slang) Signifying meritorious qualities or actions especially in regards to enjoying life, prowess at sports and success wooing potential partners.
keeping it real
adverb

(colloquial) really.

real axis 

noun
(mathematics) The horizontal line in the complex plane, every point on which corresponds to a real number

real number 

noun (pluralreal numbers)

(mathematics) An element of the real numbers; real numbers include the rational numbers and the irrational numbers, but not the imaginary numbers or complex numbers
Every integer is a real number, but not vice versa.

(computing) A floatingpoint number.
Even if you pass sqrt an integer, it returns a real number.

real part 

noun (pluralreal parts)

(complex) Of a complex number a + bi, the value a.

reciprocal 

noun

(arithmetic) Of a number, the number obtained by dividing 1 by the given number; the result of exchange, exchanging the numerator and the denominator of a fraction.

0.5 is the reciprocal of 2.
adjective (notcomp)
 Of an action, feeling, etc, done, felt, etc, by each of two people to, on or towards the other.
 In the contrary or opposite way, order, or direction

rectangle 

noun (pluralrectangles)

(geometry) A quadrilateral having opposing sides parallel and four right angles.

rectangular 

adjective
 Having a shape like a rectangle.

rectangular coordinates 

nounplural

(mathematics) A less common term for Cartesian coordinates.

rectify 

verb (rectif, i, ed)

(transitive) To correct or amend something.

(transitive, chemistry) To purify or refine, especially by distillation.

(transitive, electronics) To convert alternating current into direct current.

(transitive) To add water to alcoholic spirit to adjust its proof.

reduced 

verb

(past of, reduce)
adjective
 Made smaller or less.

prices
 In cookery, of a sauce, etc., made more concentrated.

chicken served with a red wine sauce.

refinement 

noun
 The act, or the result of refining; the removal of impurities, or a purified material
 high, Highclass style; cultivation.
 A fine or subtle distinction.

reflex angle 

noun (pluralreflex angles)

(geometry) An angle greater than 180 degrees but less than 360 degrees.

relaxation 

noun
 The act of relaxing or the state of being relaxed; the opposite of stress or tension; the aim of recreation and leisure activities.
 A diminution of tone, tension, or firmness; specifically in pathology: a looseness; a diminution of the natural and healthy tone of parts.
relaxation of the soft palate
 remission, Remission or abatement of rigor.
 Remission of attention or application.
relaxation of efforts
 unbending, Unbending; recreation; a state or occupation intended to give mental or bodily relief after effort.

(physics) The transition of an atom or molecule from a higher energy level to a lower one.

(music) The release following musical tension.

remainder 

noun
 A part or parts remain, remaining after some has/have been removed.
My son ate part of his cake and I ate the remainder.
You can have the remainder of my clothes.

(commerce) Items left unsold and subject to reduction in price.
I got a really good price on this shirt because it was a remainder.

(mathematics) The amount left over after subtracting the divisor as many times as possible from the dividend without producing a negative result. If (dividend) and d (divisor) are integers, then can always be expressed in the form n = dq + r, where q (quotation) and r () are also integers, and 0 ≤ r < d.
17 leaves a remainder of 2 when divided by 3.
11 divided by 2 is 5 remainder 1.

repeater 

noun (wikipedia, repeater, repeater (electronic device))

(electronics) an electronic device that receives a weak or lowlevel signal and retransmits it at a higher level or higher power.
 (firearms) a gun that has a store of cartridges and does not need reloading after each shot.
 (ufology and similar studies) a person who regularly sees unexplained sightings of paranormal phenomenon.
 Note " this term is more commonly used by skeptics of the paranormal, and implies that the witness lacks credibility.

result 

noun
 A flying back; resilience.
 That which results; the conclusion or end to which any course or condition of things leads, or which is obtained by any process or operation; consequence or effect; as, the result of a course of action; the result of a mathematical operation.
 The decision or determination of a council or deliberative assembly; a resolve; a decree.
verb
 To leap back; to rebound.
 To come out, or have an issue; to terminate; to have consequences;  followed by in; as, this measure will result in good or in evil.
 To proceed, spring, or rise, as a consequence, from facts, arguments, premises, combination of circumstances, consultation, thought, or endeavor.

resultant 

noun
 anything that results from something else; an outcome

(mathematics) a vector that is the vector sum of multiple vectors
adjective
 following as a result or consequence of something

rhombic 

adjective
 having the characteristics of a rhombus.

rhombohedron 

noun (pl=rhombohedra, pl2=rhombohedrons)
 A prism with six faces, each a rhombus.

rhomboid 

noun
 A parallelogram whose adjacent sides are unequal in length
 Any of several muscles that control the shoulders
adjective
 resembling, or shaped like a rhombus or rhomboid

rhombus 

noun ( rhomb, i , pl2=rhombuses)

(geometry) A parallelogram having all sides of equal length.

Riemann surface 

noun
(mathematics) a onedimensional complex manifold; a generalization of the complex plane

right 

noun
 That which complies with justice, law or reason.
''We're on the side of in this contest.
 A legal or moral entitlement.
You have no to talk to me like that!
 The right side or direction.
The pharamcy is just on the past the bookshop.

(context, Politics) The ensemble of rightwing political parties; political conservatives as a group.
The political holds too much power.
verb
 To correct
Righting all the wrongs of the war will be impossible.
 To set upright
The towtruck righted what was left of the automobile.

(intransitive) To return to normal upright position.
When the wind died down, the ship righted.
adjective

(archaic) straight, Straight, not bent.
 Having reference to a straight line; perpendicular, forming a 90degree angle.
The kitchen counter formed a angle with the back wall.
 Complying with justice, correctness or reason; correct, just, true.
I thought you'd made a mistake, but it seems you were all along.
 appropriate, Appropriate, perfectly suitable; fit for purpose.
Is this the software for my computer?
 healthy, Healthy, sane, competent.
I'm afraid my father is no longer in his mind.
 Designating the side of the body which is positioned to the east if one is facing north. This arrow points to the right: â†’
After the accident, her leg was slighly shorter than her left.

(archaic, sometimes used in titles) To a great extent or degree.
Sir, I am glad to meet you...
Members of the Queen's Privy Council are styled The Right Honourable for life.
The Right Reverend Monsignor Guido Sarducci

(context, Politics) Pertaining to the political right; conservative.
adverb
 exactly, Exactly, precisely.
The arrow landed in the middle of the target.
Luckily we arrived at the start of the film.
 very, Very, extremely, quite.
I made a stupid mistake there, didn't I?

Ann Hite, Ghost on Black Mountain,
 : The fog was hard to see through so I was on Tom Pritchard before I saw him.

right angle 

noun

(geometry) An angle of 90 degrees; the bisect of the angle formed by a single straight line.

right triangle 

noun (pl=right triangles)

(geometry) A triangle having a right angle as one of its interior angles.

Ring 

proper noun (infl, en, proper noun)
 An Irish family name.

RMS 

initialism

(context, electronics, statistics) root mean square, Root mean square.
 Railway Mail Service.
 Royal Mail Ship.

root mean square 

noun

(mathematics, of a set of numbers or values) The square root of the arithmetic mean of the squares.

Rose 

proper noun

(given name, female), vernacular form of the medieval Rosa, reinforced by the English noun rose
 A diminutive of the given name Rosemary

round 

noun
 A circular object.
 A circular or repetitious route; hospital rounds.
The guards have started their rounds; the prisoner should be caught soon.
 An outburst of a certain event. For example, a round of applause.
 A song that is sung by groups of people with each subset of people starting at a different time.
 A serving of something; a dishing out of one of something to everybody, as in a round of drinks.
 A longbristled, circularheaded paintbrush used in oil and acrylic painting.
 A bullet, or any individual ammunition shell.
 A period of time in a boxing match in which boxers are permitted to fight before being signaled to returned to their designated corner.

(context, engineering, drafting, CAD) A rounded relief or cut at an edge, especially an outside edge, added for a finished appearance and to break sharp edges.
verb (rounds, rounding, rounded)
 To shape something into a curve.
The carpenter rounded the edges of the table.

(italbrac, with "out") To finish; to complete; to fill out.
She rounded out her education with only a single mathematics class.
 To approximate a number, especially a decimal number by the closest whole number.
Ninetyfive rounds up to one hundred.
 To turn past a boundary.
Helen watched him until he rounded the corner.
 To turn and attack someone or thing.
As a group of policemen went past him, one of them rounded on him, grabbing him by the arm.
adjective (er, more)
 circular, Circular or cylindrical; having a circular crosssection in one direction.
We sat at a table to make conversation easier.
 spherical, Spherical; shaped like a ball; having a circular crosssection in more than one direction.
The ancient Egyptian demonstrated that the Earth is , not flat.
 Lacking sharp angles; having gentle curves.
Our child's bed has corners for safety.
 plump, Plump
 complete, Complete, whole, not lacking.
The baker sold us a dozen.

(mathematics) Of a number that has been rounded off or approximated.
One hundred is a nice number.

(linguistics) pronounce, Pronounced with the mouth open in the shape of an "O".
adverb
 around, Around.
=

round angle 

noun (pluralround angles)

(geometry) An angle of 360 degrees.

