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endostosis

American  
[en-do-stoh-sis, -duh-] / ˌɛn dɒˈstoʊ sɪs, -də- /

noun

Anatomy.
  1. bone formation beginning in the substance of cartilage.


endostosis British  
/ ˌɛndɒsˈtəʊsɪs /

noun

  1. the conversion of cartilage into 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

Etymology

Origin of endostosis

First recorded in 1865–70; end- + ostosis