Wikipedia
The Munach (Hebrew: , also spelled Munah or Munakh), translating to English as "to rest," is a common cantillation sound. In Sephardi and Oriental traditions it is often called Shofar holekh. It is marked with a right angle below the corresponding word.
The munach is found in various groups, including the Katon, Etnachta, and Segol groups. One or more munachs can be followed by many different trope sounds, including Zakef katon, Etnachta, Rivia, Zarka, Segol, and Pazer. It is normally used when the number of syllables in a phrase are so long that an extra note is required to accommodate all the syllables.
The munach is normally a short note. But when it is the first of two munachs followed by a Revia, it has a longer melody. In this case it may also be called legarmeh .