Meteg

Meteg (or meseg or metheg, Hebrew: מֶתֶג‎, lit. 'bridle', also gaʿya געיה‎, lit. 'bellowing', מאריך‎ maʾarikh, or מעמיד‎ maʿamid) is a punctuation mark used in Biblical Hebrew for stress marking. It is a vertical bar placed under the affected syllable.