adjective

1. not having the same center, as two circles one inside the other
2. not having the axis exactly in the center; off-center an eccentric wheel
3. not exactly circular in shape or motion
4. deviating from the norm, as in conduct; odd; unconventional

Etymology: ME eccentrik < ML eccentricus < LL eccentros, out of the center, eccentric < Gr ekkentros < ek-, out of (see ex-) + kentron, center

noun

1. a disk set off center on a shaft and revolving inside a strap that is attached to one end of a rod, thereby converting the circular motion of the shaft into back-and-forth motion of the rod
2. an odd or unconventional person