fall guy vs mug

fall guy and mug both are nouns.

Word	Noun	Adjective	Verb	Adverb
fall guy	Yes	No	No	No
mug	Yes	No	Yes	No

As nouns, fall guy and mug are synonyms defined as:

fall guy and mug: a person who is gullible and easy to take advantage of

Other synonyms of fall guy include chump, fool, gull, mark, patsy, soft touch, sucker.

fall guy (noun)	mug (noun)
a person who is gullible and easy to take advantage of	with handle and usually cylindrical
	the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
	a person who is gullible and easy to take advantage of
	the quantity that can be held in a mug

fall guy (verb)	mug (verb)
	To stare awkwardly
	rob at gunpoint or with the threat of violence