flex vs shrink

flex and shrink both are nouns.

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

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

Other hypernyms of flex include contract.

flex (noun)	shrink (noun)
the act of flexing	a physician who specializes in psychiatry

flex (verb)	shrink (verb)
cause (an object) to assume a crooked or angular form	become smaller or draw together
bend a joint	reduce in size; reduce physically
form a curve	wither, as with a loss of moisture
contract	decrease in size, range, or extent
exhibit the strength of	draw back, as with fear or pain