muff vs foul-up

muff and foul-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
muff	Yes	No	Yes	No
foul-up	Yes	No	No	No

As nouns, foul-up is a hypernym of muff; that is, foul-up is a word with a broader meaning than muff:

Other hypernyms of muff include bloomer, blooper, blunder, boner, boo-boo, botch, bungle, flub, fuckup, pratfall.

muff (noun)	foul-up (noun)
(sports) dropping the ball	an embarrassing mistake
a warm tubular covering for the hands

muff (verb)	foul-up (verb)
make a mess of, destroy or ruin
fail to catch, as of a ball