[ ˌsɪnɒ'stəʊsɪs ]
■ noun ( plural synostoses -si:z ) Physiology & Medicine the union of adjacent bones by the growth of bony substance.
Origin
C19: from syn- + Gk osteon 'bone' + -osis .
SYNOSTOSIS
Meaning of SYNOSTOSIS in English
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004