shrink vs flex

shrink and flex both are nouns.

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

As verbs, flex is a hyponym of shrink; that is, flex is a word with a more specific, narrower meaning than shrink:

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

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