• WordNet 3.6
    • n fornix 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
    • n fornix generally any arch shaped structure (but often it refers to the arched roof of an anatomical space)
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Webster's Revised Unabridged Dictionary
    • n Fornix (Anat) An arch or fold; as, the fornix, or vault, of the cranium; the fornix, or reflection, of the conjuctiva.
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Century Dictionary and Cyclopedia
    • n fornix In anat.: A median symmetrical arched formation in the brain, beneath the corpus callosum and septum lucidum, vaulting over the optic thalami and the third ventricle, and running into the floor of each lateral ventricle. In the human brain it consists of two longitudinal bundles of fibers, one on each side, which rise from the corpora albicantia, pass up, as the anterior pillars of the fornix, in front of the foramina of Monro and behind the anterior commissure, then, somewhat flattened and in apposition to each other, arch backward beneath the corpus callosum and above the velum interpositum, forming the body of the fornix, and then diverge toward the back part of the corpus callosum, to turn down, as the posterior pillars of the fornix (crura Iornicis), into the floor of the descending cornua of the lateral ventricles, where their free edges form the fimbriæ. See cut under corpus.
    • n fornix Some other arched, vaulted, or fornicated formation: as, the fornix conjunctivœ, the vault of the conjunctiva.
    • n fornix In conch.: The vaulted or excavated part of a shell under the umbo.
    • n fornix The more concavo-convex one of the shells of an inequivulve bivalve, as an oyster.
    • n fornix In botany, a small arching crest or appendage in the throat or tube of a corolla.
    • n fornix In topical geom., a part of a surface which, in conjunction with another similar part which inseparably accompanies it, increases the cyclosis of the surface by two. If cut away, it would leave two holes in the surface. Viewed from one side of the surface, it appears as a tubular bar (however much distorted or knotted) bridging the space from the edge of one hole to that of the other and leaving a transverse tunnel beneath formed by the twin fornix; while viewed from the other side it appears as a tunnel joining one hole to the other with a transverse bridge above formed by the twin fornix.
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Chambers's Twentieth Century Dictionary
    • n Fornix for′niks something resembling an arch: an arched formation of the brain.
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Webster's Revised Unabridged Dictionary
L., an arch
Chambers's Twentieth Century Dictionary


In literature:

Paget and Henry mention cases in which the corpora callosum, the fornix, and septum lucidum were imperfectly formed.
"Anomalies and Curiosities of Medicine" by George M. Gould
The lungs, like a prebend's The fornix, like a casket.
"Gargantua and Pantagruel, Complete." by Francois Rabelais
The lungs, like a prebend's The fornix, like a casket.
"Gargantua and Pantagruel, Book IV." by Francois Rabelais
If the septum be now removed, the anterior part of the fornix is brought into view.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4" by Various
Its six to twelve ducts open on to the superior fornix of the conjunctiva.
"Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 1" by Various