plunge vs dive

plunge and dive both are nouns.

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

As verbs, plunge and dive are synonyms defined as:

Other synonyms of plunge include plunk.

plunge (noun)	dive (noun)
a brief swim in water	a steep nose-down descent by an aircraft
a steep and rapid fall	a headlong plunge into water
	a cheap disreputable nightclub or dance hall

plunge (verb)	dive (verb)
begin with vigor	drop steeply
devote (oneself) fully to	swim under water
cause to be immersed	plunge into water
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