shrivel up vs shrink

shrivel up is not a noun while shrink is a noun.

Word	Noun	Adjective	Verb	Adverb
shrivel up	No	No	Yes	No
shrink	Yes	No	Yes	No

As verbs, shrivel up and shrink are synonyms defined as:

Other synonyms of shrivel up include shrivel, wither.

shrivel up (noun)	shrink (noun)
	a physician who specializes in psychiatry

shrivel up (verb)	shrink (verb)
wither, as with a loss of moisture	become smaller or draw together
	reduce in size; reduce physically
	wither, as with a loss of moisture
	decrease in size, range, or extent
	draw back, as with fear or pain