Thread:Monterossa/@comment-44439264-20200607003718/@comment-5497716-20200607064159

macron (plural macrons or macra)

(orthography) A short, straight, horizontal diacritical mark (¯) placed over any of various letters, usually to indicate that the pronunciation of a vowel is long. [from 19th c.]

https://en.wiktionary.org/wiki/macron

Long vowels

The long vowels are generally indicated by macrons ( ¯ ). Since the macron is usually missing on typewriters and people may not know how to input it on computer keyboards, the circumflex accent ( ˆ ) is often used in its place.

The long vowel u is indicated by a macron:

数学（すうがく）: {su + u} + {ga + ku} = sūgaku – mathematics

注意（ちゅうい）: {chu + u} + {i} = chūi – attention

ぐうたら: {gu + u + ta + ra} = gūtara – loafer

憂鬱（ゆううつ）: {yu + u} + {u + tsu} = yūutsu - depression

https://en.wikipedia.org/wiki/Hepburn_romanization#Long_vowels