absorb vs plunge

absorb is not a noun while plunge is a noun.

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

As verbs, absorb and plunge are synonyms defined as:

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

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

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