roast vs make fun

roast is a noun but make fun is not a noun.

Word	Noun	Adjective	Verb	Adverb
roast	Yes	Yes	Yes	No
make fun	No	No	Yes	No

As verbs, roast and make fun are synonyms defined as:

Other synonyms of roast include blackguard, guy, jest at, laugh at, poke fun, rib, ridicule.

roast (noun)	make fun (noun)
negative criticism
a piece of meat roasted or for roasting and of a size for slicing into more than one portion

roast (adjective)	make fun (adjective)
(meat) cooked by dry heat in an oven

roast (verb)	make fun (verb)
cook with dry heat, usually in an oven	subject to laughter or ridicule
subject to laughter or ridicule