flex vs gnarl

flex and gnarl both are nouns.

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

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

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

flex (noun)	gnarl (noun)
the act of flexing	something twisted and tight and swollen

flex (verb)	gnarl (verb)
cause (an object) to assume a crooked or angular form	make complaining remarks or noises under one's breath
bend a joint	twist into a state of deformity
form a curve
contract
exhibit the strength of