goofball vs harlequin

goofball and harlequin both are nouns.

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

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

goofball: a person who amuses others by ridiculous behavior
harlequin: a clown or buffoon (after the Harlequin character in the commedia dell'arte)

Other hyponyms of goofball include fool, jester, motley fool, whiteface, zany.

goofball (noun)	harlequin (noun)
a man who is a stupid incompetent fool	a clown or buffoon (after the Harlequin character in the commedia dell'arte)
a person who amuses others by ridiculous behavior

goofball (verb)	harlequin (verb)
	variegate with spots or marks