# All Words Glossary

Glossary of Math Terms
beginning with letter O
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 oblate
noun
1. (italbrac, Roman Catholic Church) A person dedicated to a life of religion or monasticism, especially a member of an order without religious vows or a lay member of a religious community.
2. A child given up by its parents into the keeping or dedication of a religious order or house.
• 2007: The Venerable Bede started as an at St Paul's, Jarrow, but by the time of his death in 735 was surely the most learned man in Europe. " Tom Shippey, "I Lerne Song", London Review of Books 29:4, p. 19
1. Flattened or depressed at the poles.
• 1922: Why should I not speak to him or to any human being who walks upright upon this orange? " James Joyce, Ulysses
• 1997: " "Tis prolate, still," with a long dejected Geordie O. "Isn"t it"?" "I"m an Astronomer," trust me, "tis gone well to ." " Thomas Pynchon, Mason & Dixon
 oblique
noun
1. (geometry) An oblique line.
2. (rare) The punctuation sign "/"
verb (obliques, obliquing, obliqued)
1. To deviate from a perpendicular line; to move in an oblique direction.
Quotations
• Projecting his person towards it in a line which obliqued from the bottom of his spine. - Sir. W. Scott.
1. (military) To march in a direction oblique to the line of the column or platoon; " formerly accomplished by oblique steps, now by direct steps, the men half- facing either to the right or left.
1. Not erect or perpendicular; neither parallel to, nor at right angles from, the base; slanting; inclined.
• It has a direction oblique to that of the former motion. - Cheyne.
1. Not straightforward; indirect; obscure; hence, disingenuous; underhand; perverse; sinister.
• The love we bear our friends . . . Hath in it certain oblique ends. - Drayton.
• This mode of oblique research, when a more direct one is denied, we find to be the only one in our power. - De Quincey.
• Then would be closed the restless, oblique eye. <br /> That looks for evil, like a treacherous spy. - Wordworth.
1. Not direct in descent; not following the line of father and son; collateral.
His natural affection in a direct line was strong, in an oblique but weak. - Baker.
1. (botany, of leaves) Having the base of the blade asymmetrical, with one side larger or extending further than the other.
 oblong
noun
1. Something with an oblong shape.
(trans-top, with an oblong shape)
• French: oblong(fr)m
(trans-mid)
(trans-bottom)
1. Describing something that is longer than it is wide.
2. Roughly rectangular or ellipsoidal.
 obtuse triangle
noun , also obtuse-angled triangle
1. (geometry) A triangle one of the angles of which is obtuse.
noun
1. a group of eight things
 octagon
noun
1. (geometry) A polygon with eight sides and eight angles.
 octagonal
1. (geometry) Shaped like an octagon, in having eight sides and eight angles.
 octahedral
1. having eight plane surfaces
 octahedron
noun (octahedr, a , pl2=octahedrons)
1. (geometry) a polyhedron with eight faces; the regular octahedron has regular triangles as faces and is one of the Platonic solids.
 octant
noun
1. The eighth part of a circle; an arc of 45 degrees.
2. (geometry): The eighth part of a disc; a sector of 45 degrees; half a quadrant.
3. (nautical): An instrument for measuring angles, particularly of elevation.
 octuple
1. Eightfold
 octuplet
noun
1. one of a group of eight babies born from the same mother during the same birth, (i.e. one of eight twins).
 odd
nounSee odds
1. (defn, English)
1. strange, unusual.
2. (arithmetic) (no comparative or superlative) Not divisible by two.
3. (rare) But for the odd exception.
4. left over, remaining when the rest have been grouped
I'm the one out.
1. casual, irregular.
He's only worked jobs.
1. (in combination with a number) about, approximately.
There were thirty- people in the room.
 one-to-one
noun (pluralone-to-ones)
1. A personal relationship, especially a sexual one, between two people. Colloquial abbreviation: 121 or 1-2-1
2. (mathematics) injection; a mapping which takes no two points in the preimage to the same point in the image
 onto
1. (mathematics) assuming each of the values in its codomain; having its range equal to its codomain (said of a function)
• Considered as a function on the real numbers, the exponential function is not onto.
 operand
noun
1. (mathematics) A quantity to which an operator is applied (in $3 - x$, the operands of the subtraction operator are 3 and $x$).
 operations research
noun (abbreviated as OR)
1. the application of scientific methods and techniques to problems of decision making
 optimization
noun
1. the design and operation of a system or process to make it as good as possible in some defined sense
 optimize
verb (optimiz, es)
1. (intransitive) To act optimistically or as an optimist.
2. (intransitive) To become optimal.
3. (transitive) To make (something) optimal.
4. (transitive) To make (something) more efficient, such as a computer program.
 order
noun
1. (uncountable) arrangement, Arrangement, disposition, sequence.
2. (uncountable) Good arrangement; opposite to chaos.
3. (countable) A command.
4. (countable) A request for some product or service.
5. (countable) A religious group.
6. (context, countable, biology, taxonomy) A rank in the classification of organisms, below class and above family; a taxon at that rank
Magnolias belong to the Magnoliales.
1. (cricket) The sequence in which a side"s batsmen bat; the batting order.
2. (electronics) a power of polynomial function in an electronic circuit"s block, such as a filter, an amplifier, etc.
• a 3-stage cascade of a 2nd-order bandpass Butterworth filter.
1. (chem) A number of a chemical reaction
• order of a reaction
1. (graphtheory) a number of vertices in a graph
2. (context, order theory) A partially ordered set.
verb
1. To set in (any) order (1).
2. To set in (a good) order (2).
3. To issue a command.
4. To request some product or service.
 ordered pair
noun (pluralordered pairs)
1. (settheory) A set containing exactly two elements in a fixed order, so that, when the elements are different, exchanging them gives a different set. Notation: (a, b) or $\langle a, b\rangle$
 ordinal number
noun
1. (arithmetic) A number used to denote position in a sequence.
"Third" is an , while "three" is a cardinal number.
1. (mathematics) A generalized kind of number to denote the size of a well-ordered set.
 ordinate
noun
1. (mathematics) the value of a coordinate on the vertical (Y) axis
1. arranged regularly in rows
 Orient
proper noun
1. Eastern countries and regions
2. East
 orthocenter
noun
1. (geometry): the intersection of the three lines that can be drawn flowing from the three corners of a triangle to a point along the opposite side where each line intersect that side at a 90 degree angle; in an acute triangle, it is inside the triangle; in an obtuse triangle, it is outside the triangle.
 orthographic
1. Of a projection used in maps, architecture etc., in which the rays are parallel.
1. Of, or relating to, orthography.
 orthonormal
1. (mathematics) Of a set of vectors, both orthogonal and normalized.
2. (mathematics) Of a linear transformation that preserves both angles and lengths.
 osculate
verbto osculate (transitive)
1. to kiss someone or something
1. (mathematics) to touch so as to have a common Wikipedia:tangent, tangent at the point of contact
to osculate (intransitive)
1. to make contact
 osculation
noun
1. the action of kissing
2. a kiss
3. a close contact
1. (mathematics) a contact between curves or surfaces, at which point they have a common tangent
 oval
noun
1. A shape rather like an egg or an ellipse.
2. A sporting arena etc. of this shape.
• Note: an ellipse is a precise mathematical shape, but an oval is not.
proper nounThe Oval
1. (Cricket) A cricket ground in South London.