1. (n.) Oddity; idiosyncrasy; deviation from the customary line of conduct\.
2. (n.) The ratio of the distance between the center and the focus of an ellipse or hyperbola to its semi-transverse axis.
3. (n.) The ratio of the distance of the center of the orbit of a heavenly body from the center of the body round which it revolves to the semi-transverse axis of the orbit.
4. (n.) The distance of the center of figure of a body, as of an eccentric, from an axis about which it turns; the throw.