mastoid process n.
A conical protuberance of the posterior portion of the temporal bone that is situated behind the ear and serves as a site of muscle attachment. Also called mastoid bone.
The part of the first pharyngeal arch in the embryo, developing into the upper jaw in the embryo.
|mastoid process (mās'toid') Pronunciation Key
A protruding bony area in the lower part of the skull that is located behind the ear in humans and many other vertebrates and serves as a site of muscle attachment. The mastoid process contains small air-filled cavities called mastoid cells that communicate with the middle ear.