flump vs plunk

flump is not a noun while plunk is a noun.

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

As verbs, flump and plunk are synonyms defined as:

flump and plunk: set (something or oneself) down with or as if with a noise

Other synonyms of flump include plank, plonk, plop, plump, plump down, plunk down.

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

flump (verb)	plunk (verb)
set (something or oneself) down with or as if with a noise	pull lightly but sharply with a plucking motion
fall heavily	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

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