crash-dive vs plunk

crash-dive is not a noun while plunk is a noun.

Word	Noun	Adjective	Verb	Adverb
crash-dive	No	No	Yes	No
plunk	Yes	No	Yes	Yes

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

Other hypernyms of crash-dive include dive, plunge.

crash-dive (noun)	plunk (noun)
	(baseball) hitting a baseball so that it drops suddenly
	a hollow twanging sound

crash-dive (verb)	plunk (verb)
descend steeply and rapidly	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

crash-dive (adverb)	plunk (adverb)
	with a short hollow thud