Rav Muvhak
The term Rav Muvhak (alternatively Rebbe Muvhak, Movhok, Movhak) refers to the person who taught one "most of his Chachmah". A simple definition for Muvhak is "primary". Typical usage is to state that a particular Rabbi's Rav Muvhak is Rabbi Aleph but he also studied/received Semikhah from Rabbi Gimmel. Rabo (alt. Ravo) means his Rav/Rebbe/Rabbi, hence the term Rabo Muvhak. Special honour must be given to a Rav Muvhak. In modern times most students are educated by a number of different rabbis so the term Rav Muvhak is now anachronistic.
Read more about this topic: Semikhah