mastoid

[mas-toid]

adjective

Anatomy.

1. of or relating to the mastoid process.

2. resembling a breast or nipple.

noun

1. the mastoid process.

mastoid

/ ˈmæstɔɪd /

adjective

1. shaped like a nipple or breast

2. designating or relating to a nipple-like process of the temporal bone behind the ear

noun

1. the mastoid process

2. informal,  mastoiditis

Other Word Forms

• intermastoid adjective
• postmastoid adjective

Word History and Origins

Origin of mastoid¹

1725–35; < New Latin mastoīdēs < Greek mastoeidḗs. See masto-, -oid

Example Sentences

In part, the look of those “big eyes” was informed by a mastoid operation that permanently damaged Ms. Keane’s hearing when she was 2.

Read more on Washington Post

From childhood, when a mastoid operation resulted in permanent eardrum damage and hearing loss, she had been fascinated with eyes, watching for cues to amplify what was being said.

Read more on New York Times

From the mastoid they created a 2-millimeter opening — roughly the width of a spaghetti noodle — into the middle ear.

Read more on Salon

But on the right side there was something else: A mass about the size of a strawberry had destroyed much of the mastoid bone just behind her ear.

Read more on New York Times

For example, a small change of direction on the mastoid process, a bony projection behind the ear, indicates whether a person has detached or attached earlobes.

Read more on The Guardian