writhe vs wriggle

writhe is not a noun while wriggle is a noun.

Word	Noun	Adjective	Verb	Adverb
writhe	No	No	Yes	No
wriggle	Yes	No	Yes	No

As verbs, writhe and wriggle are synonyms defined as:

writhe and wriggle: to move in a twisting or contorted motion, (especially when struggling)

Other synonyms of writhe include squirm, twist, worm, wrestle.

writhe (noun)	wriggle (noun)
	the act of wiggling

writhe (verb)	wriggle (verb)
to move in a twisting or contorted motion, (especially when struggling)	to move in a twisting or contorted motion, (especially when struggling)