make merry vs wassail

make merry is not a noun while wassail is a noun.

Word	Noun	Adjective	Verb	Adverb
make merry	No	No	Yes	No
wassail	Yes	No	Yes	No

As verbs, make merry and wassail are synonyms defined as:

make merry and wassail: celebrate noisily, often indulging in drinking; engage in uproarious festivities

Other synonyms of make merry include jollify, make happy, make whoopee, racket, revel, whoop it up.

make merry (noun)	wassail (noun)
	a punch made of sweetened ale or wine heated with spices and roasted apples; especially at Christmas

make merry (verb)	wassail (verb)
celebrate noisily, often indulging in drinking; engage in uproarious festivities	propose a toast to
	celebrate noisily, often indulging in drinking; engage in uproarious festivities