| Main Entry: | exoplanet |
| Part of Speech: | n |
| Definition: | an extrasolar planet; a planet that orbits a star outside of the solar system |
| Etymology: | exo- + planet |
exoplanet
any planetary body that orbits a star other than the Sun. The first extrasolar planets were discovered in 1992, and within 15 years some 250 were known.
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