FORNIX
fornix, trigonum cerebrale
(noun) an arched bundle of white fibers at the base of the brain by which the hippocampus of each hemisphere projects to the contralateral hippocampus and to the thalamus and mamillary bodies
fornix
(noun) generally any arch shaped structure (but often it refers to the arched roof of an anatomical space)
Source: WordNet® 3.1
Etymology
Noun
fornix (plural fornices)
(anatomy) An archlike structure or fold.
(anatomy) Specifically, the arched bundle of fibres or axons at the base of the brain.
Source: Wiktionary
For"nix, n.; pl. Fornices. Etym: [L., an arch.] (Anat.)
(a) An arch or fold; as, the fornix, or vault, of the cranium; the
fornix, or reflection, of the conjuctiva.
(b) Esp., two longitudinal bands of white nervous tissue beneath the
lateral ventricles of the brain.
Source: Webster’s Unabridged Dictionary 1913 Edition