passe-partout vs mounting

passe-partout and mounting both are nouns.

Word	Noun	Adjective	Verb	Adverb
passe-partout	Yes	No	No	No
mounting	Yes	No	No	No

As nouns, mounting is a hypernym of passe-partout; that is, mounting is a word with a broader meaning than passe-partout:

passe-partout (noun)	mounting (noun)
key that secures entrance everywhere	framework used for support or display
a mounting for a picture using gummed tape	an event that involves rising to a higher point (as in altitude or temperature or intensity etc.)