menu vs prix fixe

menu and prix fixe both are nouns.

Word	Noun	Adjective	Verb	Adverb
menu	Yes	No	No	No
prix fixe	Yes	Yes	No	No

As nouns, prix fixe is a hyponym of menu; that is, prix fixe is a word with a more specific, narrower meaning than menu:

Other hyponyms of menu include a la carte, table d'hote.

menu (noun)	prix fixe (noun)
an agenda of things to do	a menu listing fixed meals at fixed prices
a list of dishes available at a restaurant
(computer science) a list of options available to a computer user
the dishes making up a meal

menu (adjective)	prix fixe (adjective)
	(of a restaurant meal) complete but with limited choices and at a fixed price