nut vs nut case

nut and nut case both are nouns.

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

As nouns, nut and nut case are synonyms defined as:

Other synonyms of nut include crackpot, crank, fruitcake, screwball.

nut (noun)	nut case (noun)
a small (usually square or hexagonal) metal block with internal screw thread to be fitted onto a bolt	a whimsically eccentric person
one of the two male reproductive glands that produce spermatozoa and secrete androgens
someone who is so ardently devoted to something that it resembles an addiction
a whimsically eccentric person
usually large hard-shelled seed
half the width of an em

nut (verb)	nut case (verb)
gather nuts