eccentricity vs concentricity

eccentricity and concentricity both are nouns.

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

eccentricity (noun)	concentricity (noun)
strange and unconventional behavior	the quality of having the same center (as circles inside one another)
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