goofball vs motley fool

goofball and motley fool both are nouns.

Word	Noun	Adjective	Verb	Adverb
goofball	Yes	No	No	No
motley fool	Yes	No	No	No

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

goofball: a person who amuses others by ridiculous behavior
motley fool: a professional clown employed to entertain a king or nobleman in the Middle Ages

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

goofball (noun)	motley fool (noun)
a man who is a stupid incompetent fool	a professional clown employed to entertain a king or nobleman in the Middle Ages
a person who amuses others by ridiculous behavior