nut case vs geek

nut case and geek both are nouns.

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

As nouns, geek is a hypernym of nut case; that is, geek is a word with a broader meaning than nut case:

Other hypernyms of nut case include eccentric, eccentric person, flake, oddball.

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

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