comic vs goofball

comic and goofball both are nouns.

Word	Noun	Adjective	Verb	Adverb
comic	Yes	Yes	No	No
goofball	Yes	No	No	No

As nouns, goofball is a hyponym of comic; that is, goofball is a word with a more specific, narrower meaning than comic:

comic (noun)	goofball (noun)
a professional performer who tells jokes and performs comical acts	a man who is a stupid incompetent fool
	a person who amuses others by ridiculous behavior

comic (adjective)	goofball (adjective)
of or relating to or characteristic of comedy
arousing or provoking laughter