excentric

WordReference Random House Learner's Dictionary of American English © 2026

ec•cen•tric /ɪkˈsɛntrɪk/   adj. 

1. departing from accepted or customary character;
   unconventional;
   peculiar;
   odd;
   strange:
   eccentric behavior.

n. [countable]

2. an eccentric person.

ec•cen•tri•cal•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2026

ec•cen•tric  (ik sen′trik, ek-), adj. 

1. deviating from the recognized or customary character, practice, etc.;
   irregular;
   erratic;
   peculiar;
   odd:
   eccentric conduct; an eccentric person.
2. Mathematics [Geom.] not having the same center;
   not concentric: used esp. of two circles or spheres at least one of which contains the centers of both.
3. (of an axis, axle, etc.) not situated in the center.
4. Mechanical Engineering [Mach.] having the axis or support away from the center:
   an eccentric wheel.
5. Astronomy deviating from a circular form, as an elliptic orbit.

n. 

6. a person who has an unusual, peculiar, or odd personality, set of beliefs, or behavior pattern.
7. something that is unusual, peculiar, or odd.
8. Mechanical Engineering [Mach.] a device for converting circular motion into rectilinear motion, consisting of a disk fixed somewhat off-center to a revolving shaft, and working freely in a surrounding collar (eccen′tric strap′,) to which a rod (eccen′tric rod′) is attached.

Also,[esp. Brit.,] excentric. 

• Greek ékkentr(os) out of center (see ec-, center) + Latin -icus -ic
• Medieval Latin eccentricus
• 1350–1400

ec•cen′tri•cal, adj. 
ec•cen′tri•cal•ly, adv. 
Synonyms

• 1. strange, weird, bizarre.

Antonyms

• 1. normal, regular, ordinary, customary, conventional.