mastoid

1 of 2

adjective

mas·toid ˈma-ˌstȯid

: being the process of the temporal bone behind the ear

also : being any of several bony elements that occupy a similar position in the skull of lower vertebrates

: of, relating to, or occurring in the region of the mastoid process

mastoid

2 of 2

Examples of mastoid in a Sentence

Recent Examples on the Web

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Adjective

In severe cases, a surgeon will remove the portion of the mastoid bone that is infected. —Sherri Gordon, Health, 30 Dec. 2024

The surgeon drills through the mastoid bone, creating a path allowing the electrodes to reach the cochlea. —Kelly Burch Published, Verywell Health, 11 Dec. 2024 The electrodes on the mastoid process recorded brain activity while those on the ear were used as a ground wire. —IEEE Spectrum, 16 Mar. 2015 If left untreated, the infection could have spread to the air pockets of the mastoid bones, filling them with infected material and creating potentially life-threatening conditions like meningitis or blood clots. —Jane Recker, Smithsonian Magazine, 24 Feb. 2022 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. —New York Times, 31 Mar. 2021 Evidence of perforations were found on both sides of the skull near the mastoid bones (located just behind the ear). —Jennifer Ouellette, Ars Technica, 24 Feb. 2022 The surgeon makes an incision behind the ear to expose the mastoid bone. —Jeremy Hillpot, Discover Magazine, 5 July 2021 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. —New York Times, 28 June 2022

Noun

More were placed behind the right ear, near the mastoid, which perceives visual sensations. —IEEE Spectrum, 16 Dec. 2023 Insets: enlarged images of the cut marks in the left ear, next to the mastoid. —Jennifer Ouellette, Ars Technica, 24 Feb. 2022 But cholesteatoma tends to erode the bony wall (scutum) separating the ear canal from the mastoid, and the scutum was intact on both sides of the woman's skull. —Jennifer Ouellette, Ars Technica, 24 Feb. 2022 A doctor tried to resolve the problem with an operation on the mastoid that left him deaf in one ear. —Frederick N. Rasmussen, baltimoresun.com, 17 Aug. 2017 Part of the rear of the skull called the mastoid bears some telltale otter traits, Natural History Museum of Los Angeles paleontologist Xiaoming Wang and colleagues write, but the first molar— —Brian Switek, Smithsonian, 23 Jan. 2017

Word History

Etymology

Adjective

borrowed from New Latin mastoīdēs, borrowed from Greek mastoeidḗs "like a breast or nipple" (in mastoeideîs apophýseis "mastoid processes," from the nipple-like protuberance formed by the bone), from mastós "breast, nipple" (probably from a pre-Greek substratal language) + -oidēs -oid entry 1

Noun

by ellipsis from mastoid process, mastoid bone, etc.

First Known Use

Adjective

1732, in the meaning defined at sense 1

Noun

1840, in the meaning defined above

Time Traveler

The first known use of mastoid was in 1732

See more words from the same year

Cite this Entry

Style

“Mastoid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mastoid. Accessed 28 Apr. 2025.

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Kids Definition

mastoid

1 of 2 adjective

mas·toid ˈmas-ˌtȯid

: of, relating to, or being the mastoid process

also : occurring in the region of the mastoid process

mastoid

2 of 2 noun

: a mastoid bone or process

Medical Definition

mastoid

1 of 2 adjective

mas·toid ˈmas-ˌtȯid

: of, relating to, or being the mastoid process

also : occurring in the region of the mastoid process

mastoid

2 of 2 noun

: a mastoid bone or process

mastoid

adjective

noun

Examples of mastoid in a Sentence

Word History

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mastoid

adjective

noun

Examples of mastoid in a Sentence

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Kids Definition

Medical Definition

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