rotation vs rotary motion

rotation and rotary motion both are nouns.

Word	Noun	Adjective	Verb	Adverb
rotation	Yes	No	No	No
rotary motion	Yes	No	No	No

As nouns, rotation and rotary motion are synonyms defined as:

rotation (noun)	rotary motion (noun)
the act of rotating as if on an axis	the act of rotating as if on an axis
a planned recurrent sequence (of crops or personnel etc.)
a single complete turn (axial or orbital)
(mathematics) a transformation in which the coordinate axes are rotated by a fixed angle about the origin