geek vs screwball

geek and screwball both are nouns.

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

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

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

geek (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 carnival performer who does disgusting acts	a whimsically eccentric person

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

geek (verb)	screwball (verb)
to be intoxicated