Eccentricity

Eccentricity or eccentric may refer to:

Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"

Mathematics, science and technology

Orbital eccentricity, in astrodynamics, a measure of the non-circularity of an orbit
Eccentric anomaly, the angle between the direction of periapsis and the current position of an object on its orbit
Eccentricity vector, in celestial mechanics, a dimensionless vector with direction pointing from apoapsis to periapsis
Eccentric, a type of deferent, a circle or sphere used in obsolete epicyclical systems to carry a planet around the Earth or Sun

Eccentric (mechanism), a wheel that rotates on an axle that is displaced from the focus of the circle described by the wheel
Horizontal eccentricity, in vision, degrees of visual angle from the center of the eye
Eccentric contraction, the lengthening of muscle fibers
Eccentric position of a surveying tripod, to be able to measure hidden points
Eccentric training, the motion of an active muscle while it is lengthening under load
Eccentricity, a deviation from concentricity