What does eccentricities?

Orbital eccentricity is a very important measure of how elliptical the path is that is followed by an orbiting body. Everything that orbits around another body follows a path that is a conic section....

A line has no eccentricity

It means out of the ordinary. It can refer to behaviour which is different from the social norm, or to an orbit which is out of line with the others.

Eccentricity can describe the displacement of an applied force to an object from a line of action. The vectors pertaining to the orbit of a planet. Or non-normative behavior in a person.