oddball vs screwball

oddball and screwball both are nouns.

Word	Noun	Adjective	Verb	Adverb
oddball	Yes	No	No	No
screwball	Yes	Yes	No	No

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

Other hyponyms of oddball include crackpot, crank, fruitcake, nut, nut case, nutter, wacko, whacko.

oddball (noun)	screwball (noun)
a person with an unusual or odd personality	a pitch with reverse spin that curves toward the side of the plate from which it was thrown
	a whimsically eccentric person

oddball (adjective)	screwball (adjective)
	foolish; totally unsound