bent vs crumpled

bent is a noun but crumpled is not a noun.

Word	Noun	Adjective	Verb	Adverb
bent	Yes	Yes	No	No
crumpled	No	Yes	No	No

As adjectives, bent and crumpled are synonyms defined as:

Other synonyms of bent include dented.

bent (noun)	crumpled (noun)
a special way of doing something
a relatively permanent inclination to react in a particular way
an area of grassland unbounded by fences or hedges
grass for pastures and lawns especially bowling and putting greens

bent (adjective)	crumpled (adjective)
of metal e.g.	of metal e.g.
fixed in your purpose
used of the back and knees; stooped