mug vs stein

mug and stein both are nouns.

Word	Noun	Adjective	Verb	Adverb
mug	Yes	No	Yes	No
stein	Yes	No	No	No

As nouns, stein is a hyponym of mug; that is, stein is a word with a more specific, narrower meaning than mug:

Other hyponyms of mug include beer mug, coffee mug, toby, toby fillpot jug, toby jug.

mug (noun)	stein (noun)
with handle and usually cylindrical	a mug intended for serving beer
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

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