Definition of quaternion

• n. - The number four.
• n. - A set of four parts, things, or person; four things taken collectively; a group of four words, phrases, circumstances, facts, or the like.
• n. - A word of four syllables; a quadrisyllable.
• n. - 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.
• v. t. - To divide into quaternions, files, or companies.