Definition of "exostosis" [ex•os•to•sis]

• A bony growth on the surface of a bone or tooth. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Ringbone is the designation of the exostosis which is found on the coronet and in the digital and phalangeal regions."
• "Congenital deformity had given his face a crazed top-heaviness, for while he was so undershot that his upper gum hung in air, his forehead was so distended by exostosis that it all but hid his eyes."
• "Hallux valgus, if severe and associated with marked exostosis or bunion."