Word.ws English Dictionary

exo-

UK/ɛksəʊ-/US/ɛksoʊ-/

exo- prefix: outside; external.

Prefix

exo-

  1. outside; external
    1. extrasolar; beyond the Solar System (our solar system)
      • exo- + planet → exoplanet
      • exo- + biology → exobiology

Synonyms of exo-

Antonyms

All synonyms and antonyms of exo-

Origin of exo-

From Ancient Greek ἔξω (éxō, “outer; external”).

Words formed from exo-

  • exosemantic

Questions about exo-

What does exo- mean?
Exo- means outside; external.
What part of speech is exo-?
Exo- is a prefix.
How do you pronounce exo-?
Exo- is pronounced /ɛksoʊ-/ (US).

Words near exo- in the dictionary

  1. exnihilating
  2. exnihilation
  3. exnihilations
  4. exnovation
  5. exnovations
  6. exo-
  7. exo-cannibalism
  8. exo-Earth
  9. exo-Earths
  10. exo-isomer
  11. exo-isomers

Source and license

Adapted from Wiktionary: exo- (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “exo-.” Word.ws, https://word.ws/exo-. Based on Wiktionary, CC BY-SA 4.0.