Macron (diacritic)

A macron (/ˈmækrɒn, ˈmeɪ-/ MAK-ron, MAY-) is a diacritical mark: it is a straight bar ¯ placed above a letter, usually a vowel. Its name derives from Ancient Greek μακρόν (makrón) 'long' because it was originally used to mark long or heavy syllables in Greco-Roman metrics. It now more often marks a long vowel. In the International Phonetic Alphabet, the macron is used to indicate a mid-tone; the sign for a long vowel is instead a modified triangular colon ⟨ː⟩.

The opposite is the breve ⟨˘⟩, which marks a short or light syllable or a short vowel.

In Greco-Roman metrics and in the description of the metrics of other literatures, the macron was introduced and is still widely used in dictionaries and educational materials to mark a long (heavy) syllable. Even relatively recent classical Greek and Latin dictionaries are still concerned with indicating only the length (weight) of syllables; that is why most still do not indicate the length of vowels in syllables that are otherwise metrically determined. Many textbooks about Ancient Rome and Greece use the macron, even if it was not actually used at that time (an apex was used if vowel length was marked in Latin).

The following languages or transliteration systems use the macron to mark long vowels:

The following languages or alphabets use the macron to mark tones:

Sometimes the macron marks an omitted n or m, like the tilde, in which context it is referred to as a "nasal suspension [de]":

In romanizations of Hebrew, the macron below is typically used to mark the begadkefat consonant lenition. However, for typographical reasons a regular macron is used on p and g instead: p̄, ḡ.

The macron is used in the orthography of a number of vernacular languages of the Solomon Islands and Vanuatu, particularly those first transcribed by Anglican missionaries. The macron has no unique value, and is simply used to distinguish between two different phonemes.