1. (noun)eccentricity strange and unconventional behavior Antonyms: concentricity
2. (noun)eccentricity (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 Antonyms: concentricity
3. (noun)eccentricity a circularity that has a different center or deviates from a circular path Antonyms: concentricity