A set of four parts, things, or person; four things taken collectively; a group of four words, phrases, circumstances, facts, or the like.

A word of four syllables; a quadrisyllable.

A vector of four components; the position is contained in the first three components and an associated scalar rater is located in the last component of this four element vector. Menu

a quire of four sheets folding in two, producing eight leaves or sixteen pages

a complex number made from one real and three imaginary components

a four-dimensional vector

a group or set of four persons or things, or the quotient of two vectors

a mathematical oddity that can be used to represent rotations also

an extension of the complex number

an extension to complex numbers consisting of a vector and a scalar

an ordered-pair of a scalar and a vector, subject to the following axioms

In mathematics: an expression that is the sum of a real number and a vector and that contains four terms, one real and three imaginary. Also, the quotient of two vectors, or of two directed right lines in space, considered as depending on four geometrical elements, and as expressible by an algebraic symbol of quadrinomial form. For more information, refer to the following documents: Game Developer Magazine, Feb 1998, pages 34-42 Advanced Animation and Rendering Techniques, pages 363-365 ``Quaternion Calculus for Animation'', K. Shoemake, SIGGRAPH Proceedings Vol. 19, Number 3, 1985

In mathematics, quaternions are a non-commutative extension of complex numbers. They were first described by the Irish mathematician Sir William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space. At first, quaternions were regarded as pathological, because they disobeyed the commutative law ab = ba.