My old edition defines "Supertrunk" A cable that carries several video channels between facilities of a cable television company. A trunk between the master and the hub headends in a hub CATV system

"TRUNK" A communication line between two switching systems. The term switching systems typically includes equipment in a central office (the telephone Company) and PBXs. A tie trunk connects PBXs. Central office trunks connect a PBX to the switching system at the central office.
Again my dictionary is dated 1998 so I'm sure the definitions may be a little different.