crumple vs cave in

crumple is not a noun while cave in is a noun.

Word	Noun	Adjective	Verb	Adverb
crumple	No	No	Yes	No
cave in	Yes	No	Yes	No

As verbs, cave in is a hypernym of crumple; that is, cave in is a word with a broader meaning than crumple:

Other hypernyms of crumple include break, collapse, fall in, founder, give, give way.

crumple (noun)	cave in (noun)
	the sudden collapse of something into a hollow beneath it

crumple (verb)	cave in (verb)
become wrinkled or crumpled or creased	break down, literally or metaphorically
to gather something into small wrinkles or folds
fold or collapse
fall apart