a. [ F. excentrique, formerly also spelled eccentrique, fr. LL. eccentros out of the center, eccentric, Gr. 'e`kkentros; 'ek out of + ke`ntron center. See Ex-, and Center, and cf. Excentral. ] 1. Deviating or departing from the center, or from the line of a circle; as, an eccentric or elliptical orbit; pertaining to deviation from the center or from true circular motion. [ 1913 Webster ]

2. Not having the same center; -- said of circles, ellipses, spheres, etc., which, though coinciding, either in whole or in part, as to area or volume, have not the same center; -- opposed to concentric. [ 1913 Webster ]

3. (Mach.) Pertaining to an eccentric; as, the eccentric rod in a steam engine. [ 1913 Webster ]

4. Not coincident as to motive or end. [ 1913 Webster ]

His own ends, which must needs be often eccentric to those of his master. Bacon. [ 1913 Webster ]

5. Deviating from stated methods, usual practice, or established forms or laws; deviating from an appointed sphere or way; departing from the usual course; irregular; anomalous; odd; as, eccentric conduct. “This brave and eccentric young man.” Macaulay. [ 1913 Webster ]

He shines eccentric, like a comet's blaze. Savage. [ 1913 Webster ]

Eccentric anomaly. (Astron.) See Anomaly. --
Eccentric chuck (Mach.), a lathe chuck so constructed that the work held by it may be altered as to its center of motion, so as to produce combinations of eccentric combinations of eccentric circles. --
Eccentric gear. (Mach.) (a) The whole apparatus, strap, and other parts, by which the motion of an eccentric is transmitted, as in the steam engine. (b) A cogwheel set to turn about an eccentric axis used to give variable rotation. --
Eccentric hook or
Eccentric gab, a hook-shaped journal box on the end of an eccentric rod, opposite the strap. --
Eccentric rod, the rod that connects an eccentric strap with any part to be acted upon by the eccentric. --
Eccentric sheave, or
Eccentric pulley, an eccentric. --
Eccentric strap, the ring, operating as a journal box, that encircles and receives motion from an eccentric; -- called also eccentric hoop.

Syn. -- Irregular; anomalous; singular; odd; peculiar; erratic; idiosyncratic; strange; whimsical. [ 1913 Webster ]

n. 1. A circle not having the same center as another contained in some measure within the first. [ 1913 Webster ]

2. One who, or that which, deviates from regularity; an anomalous or irregular person or thing. [ 1913 Webster ]

3. (Astron.) (a) In the Ptolemaic system, the supposed circular orbit of a planet about the earth, but with the earth not in its center. (b) A circle described about the center of an elliptical orbit, with half the major axis for radius. Hutton. [ 1913 Webster ]

4. (Mach.) A disk or wheel so arranged upon a shaft that the center of the wheel and that of the shaft do not coincide. It is used for operating valves in steam engines, and for other purposes. The motion derived is precisely that of a crank having the same throw. [ 1913 Webster ]

Back eccentric, the eccentric that reverses or backs the valve gear and the engine. --
Fore eccentric, the eccentric that imparts a forward motion to the valve gear and the engine. [ 1913 Webster ]

a. See Eccentric. [ 1913 Webster ]

adv. In an eccentric manner. [ 1913 Webster ]

Drove eccentrically here and there. Lew Wallace. [ 1913 Webster ]

n.; pl. Eccentricities [ Cf. F. excentricité. ] 1. The state of being eccentric; deviation from the customary line of conduct; oddity. [ 1913 Webster ]

2. (Math.) The ratio of the distance between the center and the focus of an ellipse or hyperbola to its semi-transverse axis. [ 1913 Webster ]

3. (Astron.) 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. [ 1913 Webster ]

4. (Mech.) The distance of the center of figure of a body, as of an eccentric, from an axis about which it turns; the throw. [ 1913 Webster ]