Meaning of eccentricity

Definition of 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; "a circle is an ellipse with zero eccentricity"
a circularity that has a different center or deviates from a circular path

Other information on eccentricity

WIKIPEDIA results for eccentricity
Amazon results for eccentricity