CLAUSTRUM
claustrum
(noun) a layer of grey matter in the brain adjacent to the lenticular nucleus
Source: WordNet® 3.1
Etymology
Noun
claustrum (plural claustra)
(neuroanatomy) A thin, irregular sheet of grey matter underneath the inner part of the neocortex on both sides of the brains of mammals; its exact function is not understood, but it is believed to facilitate coordination between senses.
Source: Wiktionary
Claus"trum, n.; pl. Claustra. Etym: [L., a bolt or bar.] (Anat.)
Definition: A thin lamina of gray matter in each cerebral hemiphere of the
brain of man.
– Claus"tral, a.
Source: Webster’s Unabridged Dictionary 1913 Edition