plunge vs absorb

plunge is a noun but absorb is not a noun.

Word	Noun	Adjective	Verb	Adverb
plunge	Yes	No	Yes	No
absorb	No	No	Yes	No

As verbs, plunge and absorb are synonyms defined as:

Other synonyms of plunge include engross, engulf, immerse, soak up, steep.

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

plunge (verb)	absorb (verb)
begin with vigor	cause to become one with
devote (oneself) fully to	take up mentally
cause to be immersed	consume all of one's attention or time
immerse briefly into a liquid so as to wet, coat, or saturate	devote (oneself) fully to
thrust or throw into	take in, also metaphorically
fall abruptly	become imbued
drop steeply	assimilate or take in
dash violently or with great speed or impetuosity	take up, as of debts or payments
	suck or take up or in