eccentric person vs oddball

eccentric person and oddball both are nouns.

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

As nouns, eccentric person and oddball are synonyms defined as:

eccentric person and oddball: a person with an unusual or odd personality

Other synonyms of eccentric person include eccentric, flake, geek.

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