1. a combining form meaning “outside,” “outer,” “external,” used in the formation of compound words: exocentric.

Origin of exo-

<Greek, combining form of éxō outside

Words Nearby exo-

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How to use exo- in a sentence

British Dictionary definitions for exo (1 of 2)


/ (ˈɛksəʊ) /

  1. Australian an informal word for excellent

British Dictionary definitions for exo- (2 of 2)


combining form
  1. external, outside, or beyond: exobiology; exothermal

Origin of exo-

from Greek exō outside

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for exo-


  1. A prefix that means “outside” or “external,” as in exoskeleton.

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