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. (Math.) 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.
Note: 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.
--Sir W. R. Hamilton.