die back vs shrink

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

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

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

Other hypernyms of die back include shrivel, shrivel up, wither.

die back (noun)	shrink (noun)
	a physician who specializes in psychiatry

die back (verb)	shrink (verb)
suffer from a disease that kills shoots	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