questionable vs funny

questionable is not a noun while funny is a noun.

Word	Noun	Adjective	Verb	Adverb
questionable	No	Yes	No	No
funny	Yes	Yes	No	No

questionable (noun)	funny (noun)
	an account of an amusing incident (usually with a punch line)

questionable (adjective)	funny (adjective)
subject to question	arousing or provoking laughter
able to be refuted	experiencing odd bodily sensations
	not as expected
	beyond or deviating from the usual or expected