plunge vs douse

plunge is a noun but douse is not a noun.

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

As verbs, plunge and douse are synonyms defined as:

plunge and douse: immerse briefly into a liquid so as to wet, coat, or saturate

Other synonyms of plunge include dip, dunk, souse.

As verbs, douse is a hyponym of plunge; that is, douse is a word with a more specific, narrower meaning than plunge:

Other hyponyms of plunge include sop, dip, duck, dabble.

As verbs, douse is a hyponym of plunge; that is, douse is a word with a more specific, narrower meaning than plunge:

Other hyponyms of plunge include dip, dunk, dip, dunk, plunge, souse, dip, dip, submerge, submerse, soak, sheathe.

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

plunge (verb)	douse (verb)
begin with vigor	cover with liquid; pour liquid onto
devote (oneself) fully to	slacken
cause to be immersed	lower quickly
immerse briefly into a liquid so as to wet, coat, or saturate	immerse briefly into a liquid so as to wet, coat, or saturate
thrust or throw into	dip into a liquid
fall abruptly	wet thoroughly
drop steeply	put out, as of a candle or a light
dash violently or with great speed or impetuosity