mustache vs moustachio

mustache and moustachio both are nouns.

Word	Noun	Adjective	Verb	Adverb
mustache	Yes	No	No	No
moustachio	Yes	No	No	No

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

mustache: an unshaved growth of hair on the upper lip
moustachio: a large bushy moustache (with hair growing sometimes down the sides of the mouth)

mustache (noun)	moustachio (noun)
an unshaved growth of hair on the upper lip	a large bushy moustache (with hair growing sometimes down the sides of the mouth)