crackpot vs eccentric person

crackpot and eccentric person both are nouns.

Word	Noun	Adjective	Verb	Adverb
crackpot	Yes	No	No	No
eccentric person	Yes	No	No	No

As nouns, eccentric person is a hypernym of crackpot; that is, eccentric person is a word with a broader meaning than crackpot:

Other hypernyms of crackpot include eccentric, flake, geek, oddball.

crackpot (noun)	eccentric person (noun)
a whimsically eccentric person	a person with an unusual or odd personality