Breve

n. symbol over a vowel or syllable indicating a short sound

A breve (Latin brevis "short, brief") is a diacritical mark ˘, shaped like a little round cup, designed to indicate a short vowel, as opposed to the  macron ¯ which indicates long vowels. It is often used this way in dictionaries and textbooks of  Latin, Ancient Greek and some other languages, such as Tuareg. (However, there is a frequent convention of indicating only – but all – the long vowels: it is then understood that a vowel with no macron is short.) It looks similar to caron or háček, but the caron has a sharp tip, whilst the breve is rounded. Compare Ǎ ǎ Ě ě Ǐ ǐ Ǒ ǒ Ǔ ǔ (caron) with Ă ă Ĕ ĕ Ĭ ĭ Ŏ ŏ Ŭ ŭ (breve).
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Noun
1. a diacritical mark (u-curved) placed over a vowel to indicate a short sound
(hypernym) diacritical mark, diacritic

n. breve, symbol over a vowel or syllable indicating a short sound

adj. brief, short, succinct

adj. short, brief, concise, little, curt

n. breve, symbol over a vowel or syllable indicating a short sound; brief, papal letter