moustache cup vs mustache cup

moustache cup and mustache cup both are nouns.

Word	Noun	Adjective	Verb	Adverb
moustache cup	Yes	No	No	No
mustache cup	Yes	No	No	No

As nouns, moustache cup and mustache cup are synonyms defined as:

moustache cup and mustache cup: a drinking cup with a bar inside the rim to keep a man's mustache out of the drink

moustache cup (noun)	mustache cup (noun)
a drinking cup with a bar inside the rim to keep a man's mustache out of the drink	a drinking cup with a bar inside the rim to keep a man's mustache out of the drink