Jisho

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Noun
1. overline; overscore; overbarSee also 上線
Wikipedia definition
2. OverlineAn overline or overbar or overscore (coined in analogy to underline and underscore, attested for mathematical notation since 1899), refers to the typographical feature of a line drawn immediately above the text, for example used to indicate medieval sigla. Specifically, a line drawn over one symbol is a macron, and a line over a collection of symbols is a vinculum. Marking one or more words with a continuous line above the characters is also described as "overstriking".
Read “Overline” on English Wikipedia
Read “オーバーライン” on Japanese Wikipedia
Read “Overline” on DBpedia

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