Definition of claustrum in US English:

claustrum

noun

Anatomy
  • A thin layer of gray matter in each cerebral hemisphere between the lentiform nucleus and the insula.

    • ‘On each side, the ventral aspect of the claustrum and the subdivisions of the lentiform nucleus (putamen, medial and lateral parts of globus pallidus) are seen lateral to the optic tracts.’

Origin

Mid 19th century: Latin, literally ‘lock, enclosed place’.

Pronunciation

claustrum

/ˈklôstrəm/