rotation vs rotary

rotation and rotary both are nouns.

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

rotation (noun)	rotary (noun)
the act of rotating as if on an axis	a road junction at which traffic streams circularly around a central island
a planned recurrent sequence (of crops or personnel etc.)	electrical converter consisting of a synchronous machine that converts alternating to direct current or vice versa
a single complete turn (axial or orbital)
(mathematics) a transformation in which the coordinate axes are rotated by a fixed angle about the origin

rotation (adjective)	rotary (adjective)
	relating to or characterized by rotation
	describing a circle; moving in a circle