# quaternion

[kwuh-tur-nee-uh n]

### noun

a group or set of four persons or things.

Bookbinding. four gathered sheets folded in two for binding together.

Mathematics.

- an expression of the form a + bi + cj + dk, where a, b, c, and d are real numbers; i2 = j2 = k2 = −1; and ij = −ji = k, jk = −kj = i, and ki = −ik = j.
- a quantity or operator expressed as the sum of a real number and three complex numbers, equivalent to the quotient of two vectors. The field of quaternions is not commutative under multiplication.

## Origin of quaternion

1350–1400; Middle English quaternioun < Late Latin quaterniōn- (stem of quaterniō), equivalent to Latin quatern(ī) four at a time + -iōn- -ion

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Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

## Related Words for quaternion

tetralogy, tetrad, quaternity, quadrivium, quadruplet, quadruple, quaternion, quaternary, quadrumvirate, quartet, quadrigeminal## Examples from the Web for quaternion

### Historical Examples of quaternion

Even then the captain of the gate was replying to a question from the quaternion.

Ulric the JarlWilliam O. Stoddard

Should neither player be able to form a quaternion, then the game is drawn.

The quaternion was a gathering of four sheets of vellum, each folded once; thus forming sixteen pages.

Illuminated Manuscripts in Classical and Mediaeval TimesJ. Henry Middleton

William Hare, the second of our quaternion, was also a native of Ireland, having been born in the neighbourhood of Londonderry.

The Court of CacusAlexander Leighton

As regard class of the first quaternion, like Sancho Panza I have no intention of indicating how old these may be.

Legends & Romances of SpainLewis Spence

## quaternion

### noun

## Word Origin for quaternion

C14: from Late Latin quaterniōn, from Latin quaternī four at a time

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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## quaternion

[kwə-tûr′nē-ən]

The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.