gnarl vs flex

gnarl and flex both are nouns.

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

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

Other hypernyms of gnarl include bend, deform, turn, twist.

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

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