Definition of mastoid bone in English:

mastoid bone

noun

  • The posterior portion of the temporal bone in humans and other mammals, which includes the mastoid process. Formerly also: †designating any of several bones of the skull in other vertebrates, regarded as homologous with this part of the temporal bone (obsolete). Also (chiefly in Medicine): = "mastoid process".

Origin

Mid 19th century; earliest use found in Robert Edmond Grant (1793–1874), comparative anatomist and transmutationist.