• synonyms


[ek-so-stoh-sis, -suh-]
noun, plural ex·os·to·ses [ek-so-stoh-seez, -suh-] /ˌɛk sɒˈstoʊ siz, -sə-/. Pathology.
  1. the abnormal formation of a bony growth on a bone or tooth.
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Origin of exostosis

1730–40; < New Latin < Greek exóstōsis an outgrowth. See ex-3, ostosis
Related formsex·os·tosed, adjectiveex·os·tot·ic [ek-so-stot-ik, -suh-] /ˌɛk sɒˈstɒt ɪk, -sə-/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for exostosis

Historical Examples

  • This change may consist of induration, exostosis, or even anchylosis.

    Special Report on Diseases of Cattle

    U.S. Department of Agriculture

  • It may be of the natural form and size, but the passage through it more or less obstructed by exostosis.

  • Ringbone is the designation of the exostosis which is found on the coronet and in the digital and phalangeal regions.

    Special Report on Diseases of the Horse

    United States Department of Agriculture

  • This affection, popularly termed bone spavin, is an exostosis of the hock joint.

    Special Report on Diseases of the Horse

    United States Department of Agriculture

  • As a result there is a marked depression at the coronet, the depression being heightened in effect by the exostosis in front.

    Diseases of the Horse's Foot

    Harry Caulton Reeks

British Dictionary definitions for exostosis


noun plural -ses (-siːz)
  1. an abnormal bony outgrowth from the surface of a bone
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Word Origin

C18: via New Latin from Greek, from ex- 1 + osteon bone
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

exostosis in Medicine


n. pl. -ses (-sēz)
  1. A projection that is capped by cartilage and arises from a bone that develops from cartilage.hyperostosis poroma
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.