fornix
noun
any of various arched or vaulted structures, as an arching fibrous formation in the brain.
The grammatical form denoting more than one person, place, thing, or idea.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Olry and Haines point out that Roman architects during the first century B.C. created wooden rooms with vaulted ceilings, called fornices.
From Slate ● May 17, 2011