osteopetrosis
/ˌɒstɪəʊpɪˈtrəʊsɪs/Medicine and Veterinary Med.
noun
Any of a group of inherited disorders (in humans and other mammals) characterized by thickening of the bones due to defective bone resorption by osteoclasts. Also: a proliferative bone disorder caused by retroviral infection (avian leukosis complex) in birds.
Origin
1920s. From osteo- + ancient Greek πέτρα rock + -osis.