Definition of mastoid in US English:

mastoid

adjective

Anatomy
  • Relating to the mastoid process.

    ‘mastoid disease’
    • ‘Cholesterol granuloma is usually associated with chronic middle ear disease and is common in the mastoid antrum and air cells of the temporal bone.’
    • ‘Common to all of these patients is an abnormal connection between the sterile subarachnoid space, and the sinonasal region, middle ear cleft and mastoid cavity.’
    • ‘A CT scan enables assessment of the degree of aeration of the middle ear cleft and mastoid cavity and a bone scan may detect osteomyelitis.’
    • ‘The relationship between middle ear disease and mastoid development remains unclear although it is known that poor mastoid development is associated with middle ear disease.’
    • ‘A review of the literature shows fluctuating trends in the numerous techniques that have been developed and used by otologists throughout the years of mastoid surgery.’

noun

Anatomy
  • 1The mastoid process.

    • ‘The group of patients underwent modified radical mastoidectomy because of the presence of a sclerotic mastoid with extensive cholesteatoma.’
    • ‘The mastoid was poorly developed, with a clear fluid effusion throughout with no evidence of cholesteatoma or inflammatory disease.’
    • ‘They were implanted in the mastoid, frontal and maxillary regions for periods of 1 week to 2 months.’
    • ‘Longstanding cholesteatomas expand to involve the mastoid, inner ear, and facial nerve.’
    • ‘The temporal bone is the first bone to be affected, with imminent involvement of the petrous apex and mastoid.’
    1. 1.1informal treated as singular Mastoiditis.

Origin

Mid 18th century: via French and modern Latin from Greek mastoeidēs ‘breast-shaped’, from mastos ‘breast’.

Pronunciation

mastoid

/ˈmæstɔɪd//ˈmastoid/