English Reference
adjective · noun

eccentric

adj. · n.
US /ˌɛkˈsɛntɹɪk/ UK /ɛksˈɛntɹɪk/ ec·cen·tric UK spelling eccentric's, eccentric's

  1. 01 B2 Upper Intermediate

    adj.behaving in a way that is slightly strange or unusual, but often in a harmless or interesting way.

    adj.deviating from established social norms or conventional patterns; typically used to describe personality or lifestyle in a non-pejorative way.

    Simple

    The old professor was known for his eccentric habit of wearing two different shoes.

    In context

    Her eccentric lifestyle, which included living in a converted lighthouse and keeping a pet llama, made her a local celebrity.

  2. 02 C1 Advanced Technical Science

    adj.not perfectly round; having an oval or elliptical shape.

    adj.deviating from a perfect circle; in astronomy, describing an orbit that is elliptical rather than circular.

    Simple

    The planet follows an eccentric path around its star.

    In context

    The comet's highly eccentric orbit brings it close to the sun only once every few centuries, spending most of its time in the outer solar system.

  3. 03 C1 Advanced Technical

    adj.not placed in the middle or having a different center point than something else.

    adj.not situated in the center; having a different center from another geometric figure.

    Simple

    The designer chose an eccentric layout for the buttons to make the jacket look unique.

    In context

    The engineer noted that the eccentric placement of the weight was causing the machine to vibrate excessively at high speeds.

    off centerasymmetrical
  4. 04 B2 Upper Intermediate

    n.a person who has unusual habits or beliefs.

    n.an individual who deviates from conventional or accepted social behaviour.

    Simple

    The town was full of eccentrics who didn't care what their neighbours thought.

    In context

    History remembers him as a brilliant eccentric who spent his entire fortune on a failed attempt to build a flying machine.

    characterindividualistnonconformist
    conformist
  5. 05 C2 Proficiency Technical Engineering

    n.a wheel or part of a machine that is not fixed in the center, used to change circular motion into straight motion.

    n.a disk or wheel mounted off-center on a shaft, used to convert rotary motion into reciprocating motion.

    Simple

    The steam engine uses an eccentric to move the valves back and forth.

    In context

    The technician adjusted the eccentric on the drive shaft to ensure the piston reached its full range of motion without striking the cylinder head.

    cam

I've got no idea why this was done." Pakistan have a history of making eccentric decisions in the wake of defeats.

BBC News· 31 Aug 2026

Here, the eccentric inventor Mrs Armitage makes repeated attempts to visit her cousin two villages down.

The Guardian· 18 Aug 2026

From Middle French excentrique, from Medieval Latin eccentricus, from Ancient Greek ἔκκεντρος (ékkentros, “not having the earth as the center of an orbit”), from ἐκ (ek, “out”) + κέντρον (kéntron, “point”). Equivalent to ex- + -centric.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Ancient Greek ἔκκεντρος
Level B2 · Upper Intermediate
Frequency Frequent
Updated