GNU Collaborative International Dictionary of English

Found one definition

1.       
   Platen (?), n. [F. platine, fr. plat flat. See Plate, and cf. Platin.] (Mach.) (a) The part of a printing press which presses the paper against the type and by which the impression is made. (b) Hence, an analogous part of a typewriter, on which the paper rests to receive an impression. (c) The movable table of a machine tool, as a planer, on which the work is fastened, and presented to the action of the tool; -- also called table.
   
   [1913 Webster]