Definition of "mastoid"

(anatomy) Being the process of the temporal bone behind the ear.

1. (zootomy) Being any of several bony elements that occupy a similar position in the skull of lower vertebrates.  examples

(anatomy) Of or relating to the mastoid process of the temporal bone.  examples

(anatomy) Ellipsis of mastoid process..  examples

(pathology, informal) Clipping of mastoiditis.