noun
Refers to the symbol (ー) used in Japanese kana writing to indicate a long vowel, or the macron (¯) used in romanization.
カタカナの「コーヒー」の「ー」は長音記号です。
The 'ー' in the katakana word 'コーヒー' is a long-vowel mark.
ローマ字で長
When indicating long vowels in romanization, a macron (long-vowel mark) is sometimes used.