carouse vs whoop it up

carouse is a noun but whoop it up is not a noun.

Word	Noun	Adjective	Verb	Adverb
carouse	Yes	No	Yes	No
whoop it up	No	No	Yes	No

As verbs, whoop it up is a hypernym of carouse; that is, whoop it up is a word with a broader meaning than carouse:

carouse: engage in boisterous, drunken merrymaking
whoop it up: celebrate noisily, often indulging in drinking; engage in uproarious festivities

Other hypernyms of carouse include jollify, make happy, make merry, make whoopee, racket, revel, wassail.

carouse (noun)	whoop it up (noun)
revelry in drinking; a merry drinking party

carouse (verb)	whoop it up (verb)
engage in boisterous, drunken merrymaking	celebrate noisily, often indulging in drinking; engage in uproarious festivities