rotary vs rotation

rotary and rotation both are nouns.

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

rotary (noun)	rotation (noun)
a road junction at which traffic streams circularly around a central island	the act of rotating as if on an axis
electrical converter consisting of a synchronous machine that converts alternating to direct current or vice versa	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

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