macron

UK: /ˈmækrɒn/ US: (mā′kron, mak′ron)

WordReference Random House Unabridged Dictionary of American English © 2026

ma•cron  (mā′kron, mak′ron), n. 

1. Phonetics a horizontal line used as a diacritic over a vowel to indicate that it has a long sound or other specified pronunciation, as (ā) in fate (fāt).

• noun, nominal use of Greek makrón, neuter of makrós long. See macro- 1850–55

Collins Concise English Dictionary © HarperCollins Publishers::

macron / ˈmækrɒn/ noun

1. a diacritical mark (¯) placed over a letter, used in prosody, in the orthography of some languages, and in several types of phonetic respelling systems, to represent a long vowel

Etymology: 19th Century: from Greek makron something long, from makros long