\▐ram\ n [ME, fr. OE ramm; akin to OHGr ram] (before 12c) In compression and matched-die molding, the press member that enters the cavity block and exerts pressure on the molding compound, designated by its position in the assembly as the top force or bottom force. In older injection machines predating the development of screw injection, the plunger that forced the feed pellets through the annulus between cylinder and torpedo, and that also accomplished, in most such machines, the injection of melt into the mold. Very few of these machines are still (1993) in commercial use. The piston of a melt accumulator such as may be used in blow molding large objects, or in special injection-molding techniques. The piston or plunger of a ram extruder.