Definitions for "Kohen"
priests, the descendants of Aaron
The hereditary caste of priests in biblical times. (Plural— Kohanim) Since the destruction of the Temple in the year 70 CE their separate status and genealogy is in doubt.
a patrilineal descendant of the Biblical personality Aaron
a very important part of the Jewish religion with a range of responsibilities and restrictions and yes, the surname comes from their title being used as the surname