tibiotarsus Syllabification: (tib·i·o·tar·sus)Pronunciation: /ˌtibēōˈtärsəs/Definition of tibiotarsus noun (plural tibiotarsi /-sī/) Zoology the bone in a bird’s leg corresponding to the tibia, fused at the lower end with some bones of the tarsus. Origin: late 19th century: blend of tibia and tarsustibiotarsus in other Oxford dictionaries Definition of tibiotarsus in the British & World English dictionary