roister vs whoop it up

roister and whoop it up both are verbs.

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

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

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

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

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