fornix

Estimated CEFR level: C2 — Proficiency

Estimated from word frequency; not an official CEFR classification.

Definition

noun generally any arch shaped structure (but often it refers to the arched roof of an anatomical space)
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

Borrowing from Latin fornix (“an arch, vault”).

The lungs, like a prebend’s The fornix, like a casket. fur-gown. — Gargantua and Pantagruel, François Rabelais
These arcade dens were called “fornices,” from which comes our generic fornication. — The Satyricon — Complete, Petronius Arbiter

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