1. (n.)quaternion a group or set of four persons or things.
2. quaternion a generalization of a complex number to four dimensions with three different imaginary units in which a number is represented as the sum of a real scalar and three real numbers multiplying each of the threeimaginary units.
Etymology: (1350–1400; ME quaternioun < LL quaterniō= L quatern(ī) four at a time +-iō -ion)
Definition of 'Quaternion'
Princeton's WordNet
1. (noun)four, 4, IV, tetrad, quatern, quaternion, quaternary, quaternity, quartet, quadruplet, foursome, Little Joe the cardinal number that is the sum of three and one
2. (noun)Quaternion a set of four parts, things, or person; fourthings taken collectively; a group of four words, phrases, circumstances, facts, or the like
3. (noun)Quaternion a word of four syllables; a quadrisyllable
4. (noun)Quaternion 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
5. (verb)Quaternion to divide into quaternions, files, or companies
Definitions of Quaternion 
