Definition of inion in English:

inion

Pronunciation /ˈinēän/ /ˈɪniɑn/

noun

Anatomy
  • The projecting part of the occipital bone at the base of the skull.

    ‘In these cases, the inion may be greatly enlarged.’
    • ‘There is a slight occipital bunning and a very robust nuchal plane, inion, and mastoid/supramastoid region.’
    • ‘For instance, bone thickness at inion averages 10.3 mm for A. afarensis and 12.8 mm for A. africanus.’

Origin

Early 19th century from Greek, literally ‘nape of the neck’.