. . . "A macron (/\u02C8m\u00E6kr\u0252n, \u02C8me\u026A-/) is a diacritical mark, a straight bar ( \u00AF ) placed above a letter, usually a vowel. Its name derives from the Greek makr\u00F3n (\u03BC\u03B1\u03BA\u03C1\u03CC\u03BD) meaning \"long\" and was originally used to mark long or heavy syllables in Greco-Roman metrics. It now more often marks a long vowel."@en . . . .