'Breve' definitions:

Definition of 'breve'

noun

A diacritical mark (U-shaped) placed over a vowel to indicate a short sound

From: GCIDE

Breve \Breve\ (br[=e]v), n. [It. & (in sense 2) LL. breve, fr. L. brevis short. See Brief.]
1. (Mus.) A note or character of time, equivalent to two semibreves or four minims. When dotted, it is equal to three semibreves. It was formerly of a square figure (as thus: ? ), but is now made oval, with a line perpendicular to the staff on each of its sides; -- formerly much used for choir service. --Moore. [1913 Webster]
2. (Law) Any writ or precept under seal, issued out of any court. [1913 Webster]
3. (Print.) A curved mark [[breve]] used commonly to indicate the short quantity of a vowel. [1913 Webster]
4. (Zool.) The great ant thrush of Sumatra (Pitta gigas), which has a very short tail. [1913 Webster]