shrink back vs cringe

shrink back is not a noun while cringe is a noun.

Word	Noun	Adjective	Verb	Adverb
shrink back	No	No	Yes	No
cringe	Yes	No	Yes	No

As verbs, cringe is a hypernym of shrink back; that is, cringe is a word with a broader meaning than shrink back:

Other hypernyms of shrink back include flinch, funk, quail, recoil, shrink, squinch, wince.

shrink back (noun)	cringe (noun)
	A posture or gesture of shrinking or recoiling.
	some event or object that causes embarrassment and shame

shrink back (verb)	cringe (verb)
pull away from a source of disgust or fear	show submission or fear
	draw back, as with fear or pain