flex vs convolve

flex is a noun but convolve is not a noun.

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

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

Other hyponyms of flex include dent, indent, incurvate, gnarl, crank, convolute.

flex (noun)	convolve (noun)
the act of flexing

flex (verb)	convolve (verb)
cause (an object) to assume a crooked or angular form	curl, wind, or twist together
bend a joint
form a curve
contract
exhibit the strength of