### Definition of Quaternion

1. Noun. The cardinal number that is the sum of three and one.

### Definition of Quaternion

1. n. The number four.

2. v. t. To divide into quaternions, files, or companies.

### Definition of Quaternion

1. Noun. A group or set of four people or things. ¹

2. Noun. (mathematics) A four-dimensional hypercomplex number that consists of a real dimension and 3 imaginary ones (''i'', ''j'', ''k'') that are each a square root of -1. They are commonly used in vector mathematics and in calculating the rotation of three-dimensional objects. ¹

¹ Source: wiktionary.com

1. [n -S]

### Medical Definition of Quaternion

1. 1. The number four. 2. A set of four parts, things, or person; four things taken collectively; a group of four words, phrases, circumstances, facts, or the like. "Delivered him to four quaternions of soldiers." (Acts xii. 4) "Ye elements, the eldest birth Of Nature's womb, that in quaternion run." (Milton) "The triads and quaternions with which he loaded his sentences." (Sir W. Scott) 3. A word of four syllables; a quadrisyllable. 4. 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. The science or calculus of quaternions is a new mathematical method, in which the conception of a quaternion is unfolded and symbolically expressed, and is applied to various classes of algebraical, geometrical, and physical questions, so as to discover theorems, and to arrive at the solution of problems. Origin: L. Quaternio, fr.quaterni four each. See Quaternary. Source: Websters Dictionary (01 Mar 1998)

### Quaternion Pictures

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### Lexicographical Neighbors of Quaternion

 quaternarilyquaternaristquaternaristsquaternarizationquaternaryquaternary ammoniumquaternary ammonium compoundquaternary ammonium compoundsquaternary carbon atomquaternary industry quaternary structurequaternary syphilisquaternatequaternationquaternationsquaternion (current term)quaternionicquaternionistquaternionistsquaternions quaternitiesquaternityquaternizationquateronquateronsquaterpolymerquaterpolymersquatorzainquatorzainsquatorze

### Literary usage of Quaternion

Below you will find example usage of this term as found in modern and/or classical literature:

1. An Elementary Treatise on Quaternions by Peter Guthrie Tait (1890)
"And precisely similar remarks apply to partial differentiation of a quaternion function of any number of scalar independent variables. ..."

2. Elements of Quaternions by William Rowan Hamilton (1899)
"238, And with coplanar quaternion exponents, p. 268.] SECTION 4.—On the Ponential and Logarithm of a quaternion ; and on Powers of quaternions, ..."

3. Proceedings of the Cambridge Philosophical Society by Cambridge Philosophical Society (1892)
"(2) On quaternion Functions, with especial Reference to the Discussion of Laplace's Equation. By J. BRILL, MA, St John's College. 1. ..."

4. Aristotle by George Grote (1872)
"The new quaternion of propositions, with non homo as subject, will stand thus— (quaternion II.) (E) Est Justus non homo (F) Non est Justus non homo. ..."

5. Chambers's Encyclopaedia: A Dictionary of Universal Knowledge for the People (1868)
"... and therefore q depends upon four independent numerical quantities ; hence its name, quaternion. A similar investigation, but somewhat less elementary, ..."