roast vs poke fun

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

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

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

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

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

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