Maran
Maran is a title for exceptionally respected rabbis. The term is more prevalent among Sephardi Jews, but is also widely used by Ashkenazi Haredi Jews.
It is an Aramaic word used frequently in the Talmud which means 'our master' (מָרַן, māran, 'our master'). Most often, as the translation indicates, it is given to rabbis who are considered influential teachers and leaders.