mesonychid
/ˈmɛzəʊˌnʌɪkɪd/noun
A member of the extinct family Mesonychidae of carnivorous ungulates, known from fossils of the middle to late Palaeocene epoch.
adjective
Belonging to, characteristic of, or designating the family Mesonychidae.
Origin
Late 19th century; earliest use found in Isaac Funk (1839–1912), publisher and reformer. From scientific Latin Mesonychidae, family name from Mesonyx, genus name from meso- + ancient Greek ὄνυξ nail + -idae.