Concentric Definition

kən-sĕntrĭk

adjective

Having a center in common.

Concentric circles.

Webster's New World

(geometry) Having a common center.

Wiktionary

(physiology) (of a motion) In the direction of contraction of a muscle. (E.g. extension of the lower arm via the elbow joint while contracting the triceps and other elbow extensor muscles; closing of the jaw while flexing the masseter).

Antonym: eccentric. Concentric and eccentric movements are collectively referred to as isotonic (with motion), the antonym of which is isometric (without motion).

Wiktionary

Synonyms:

Synonyms:
homocentric
concentrical

Antonyms:

Antonyms:
eccentric

Origin of Concentric

Middle English, from Middle French concentrique, from Medieval Latin concentricus, from Latin con- (“with, together”) + centrum (“circle, center”)

From Wiktionary
Middle English concentrik from Medieval Latin concentricus Latin com- com- Latin centrum center center

From American Heritage Dictionary of the English Language, 5th Edition