noun Astronomy.
a planet that revolves around a star other than the sun.

1970–75; exo- + planet

exoplanetary, adjective
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World English Dictionary
exoplanet (ˈɛksəʊˌplænɪt)
a planet that orbits a star in a solar system other than that of Earth

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
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Dictionary.com's 21st Century Lexicon
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
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American Heritage
Science Dictionary
exoplanet   (ěk'sō-plān'ĭt)  Pronunciation Key 
See extrasolar planet.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Britannica


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.

Learn more about exoplanet with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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