flop vs come down

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

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

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

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

flop (noun)	come down (noun)
the act of throwing yourself down; collapse; sink
a complete failure
someone who is unsuccessful
an arithmetic operation performed on floating-point numbers

flop (verb)	come down (verb)
fall suddenly and abruptly	get sick
fall loosely	be the essential element
fail utterly; collapse	criticize or reprimand harshly
	move downward and lower, but not necessarily all the way
	fall from clouds

flop (adverb)	come down (adverb)
with a flopping sound
completely