melorheostosis

noun
melo·​rhe·​os·​to·​sis | \ ˌmel-ə-ˌrē-äs-ˈtō-səs How to pronounce melorheostosis (audio) \
plural melorheostoses\ -​ˌsēz How to pronounce melorheostoses (audio) \ or melorheostosises

Medical Definition of melorheostosis

: an extremely rare form of osteosclerosis of unknown etiology characterized by asymmetrical or local enlargement and sclerotic changes in the long bones of one extremity