atrophy vs shrink

atrophy and shrink both are nouns.

Word	Noun	Adjective	Verb	Adverb
atrophy	Yes	No	Yes	No
shrink	Yes	No	Yes	No

As verbs, shrink is a hypernym of atrophy; that is, shrink is a word with a broader meaning than atrophy:

Other hypernyms of atrophy include shrivel, shrivel up, wither.

atrophy (noun)	shrink (noun)
any weakening or degeneration (especially through lack of use)	a physician who specializes in psychiatry
a decrease in size of an organ caused by disease or disuse

atrophy (verb)	shrink (verb)
undergo atrophy	become smaller or draw together
	reduce in size; reduce physically
	wither, as with a loss of moisture
	decrease in size, range, or extent
	draw back, as with fear or pain