ostosis (?s?t??s?s) or osteosisn (Physiology) the formation of bone; ossificationCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ostosisossification or the process of bone formation.See also: Bones-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.