Medical Definition of Mastoid

Mastoid: The rounded protrusion of bone just behind the ear. The mastoid was once thought to look like a breast (hence its name).

Last Editorial Review: 3/19/2012

Search MedTerms:

Back to MedTerms online medical dictionary A-Z List
Pill Identifier Tool

Need help identifying pills and medications?
Use the pill finder tool on RxList.

Health Solutions From Our Sponsors