nosedive vs plunk

nosedive and plunk both are nouns.

Word	Noun	Adjective	Verb	Adverb
nosedive	Yes	No	Yes	No
plunk	Yes	No	Yes	Yes

As verbs, plunk is a hypernym of nosedive; that is, plunk is a word with a broader meaning than nosedive:

Other hypernyms of nosedive include dive, plunge.

nosedive (noun)	plunk (noun)
a steep nose-down descent by an aircraft	(baseball) hitting a baseball so that it drops suddenly
a sudden sharp drop or rapid decline	a hollow twanging sound

nosedive (verb)	plunk (verb)
plunge nose first; drop with the nose or front first, of aircraft	pull lightly but sharply with a plucking motion
	set (something or oneself) down with or as if with a noise
	drop steeply
	make or move along with a sound as of a horse's hooves striking the ground

nosedive (adverb)	plunk (adverb)
	with a short hollow thud