plunk vs come down

plunk is a noun but come down is not a noun.

Word	Noun	Adjective	Verb	Adverb
plunk	Yes	No	Yes	Yes
come down	No	No	Yes	No

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

Other hypernyms of plunk include descend, fall, go down.

plunk (noun)	come down (noun)
(baseball) hitting a baseball so that it drops suddenly
a hollow twanging sound

plunk (verb)	come down (verb)
pull lightly but sharply with a plucking motion	get sick
set (something or oneself) down with or as if with a noise	be the essential element
drop steeply	criticize or reprimand harshly
make or move along with a sound as of a horse's hooves striking the ground	move downward and lower, but not necessarily all the way
	fall from clouds

plunk (adverb)	come down (adverb)
with a short hollow thud