geek vs nut case

geek and nut case both are nouns.

Word	Noun	Adjective	Verb	Adverb
geek	Yes	No	Yes	No
nut case	Yes	No	No	No

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

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

geek (noun)	nut case (noun)
a person with an unusual or odd personality	a whimsically eccentric person
a carnival performer who does disgusting acts

geek (verb)	nut case (verb)
to be intoxicated