crackpot vs oddball

crackpot and oddball both are nouns.

Word	Noun	Adjective	Verb	Adverb
crackpot	Yes	No	No	No
oddball	Yes	No	No	No

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

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

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