eccentric vs eccentricity

eccentric and eccentricity both are nouns.

Word	Noun	Adjective	Verb	Adverb
eccentric	Yes	Yes	No	No
eccentricity	Yes	No	No	No

eccentric (noun)	eccentricity (noun)
a person with an unusual or odd personality	strange and unconventional behavior
a person of a specified kind (usually with many eccentricities)	a circularity that has a different center or deviates from a circular path
	(geometry) a ratio describing the shape of a conic section; the ratio of the distance between the foci to the length of the major axis

eccentric (adjective)	eccentricity (adjective)
not having a common center; not concentric
conspicuously or grossly unconventional or unusual