whacko vs eccentric person

whacko and eccentric person both are nouns.

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

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

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

whacko (noun)	eccentric person (noun)
a person who is regarded as eccentric or mad	a person with an unusual or odd personality