drink in vs plunge

drink in is not a noun while plunge is a noun.

Word	Noun	Adjective	Verb	Adverb
drink in	No	No	Yes	No
plunge	Yes	No	Yes	No

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

Other hypernyms of drink in include absorb, engross, engulf, immerse, soak up, steep.

drink in (noun)	plunge (noun)
	a brief swim in water
	a steep and rapid fall

drink in (verb)	plunge (verb)
be fascinated or spell-bound by; pay close attention to	begin with vigor
	devote (oneself) fully to
	cause to be immersed
	immerse briefly into a liquid so as to wet, coat, or saturate
	thrust or throw into
	fall abruptly
	drop steeply
	dash violently or with great speed or impetuosity