Source : Webster's Revised Unabridged Dictionary (1913)

Stamp \Stamp\v. t. [imp. & p. p. {Stamped}; p. pr. & vb. n.
   {Stamping}.] [OE. stampen; akin to LG. & D. stampen, G.
   stampfen, OHG. stanpf?n, Dan. stampe, Sw. stampa, Icel.
   stappa, G. stampf a pestle and E. step. See {Step}, v. i.,
   and cf. {Stampede}.]
   1. To strike beat, or press forcibly with the bottom of the
      foot, or by thrusting the foot downward. --Shak.

            He frets, he fumes, he stares, he stamps the ground.
                                                  --Dryden.

   2. To bring down (the foot) forcibly on the ground or floor;
      as, he stamped his foot with rage.

   3. To crush; to pulverize; specifically (Metal.), to crush by
      the blow of a heavy stamp, as ore in a mill.

            I took your sin, the calf which ye had made, and
            burnt it with fire, and stamped it, and ground it
            very small.                           --Deut. ix.
                                                  21.

   4. To impress with some mark or figure; as, to stamp a plate
      with arms or initials.

   5. Fig.: To impress; to imprint; to fix deeply; as, to stamp
      virtuous principles on the heart.

            God . . . has stamped no original characters on our
            minds wherein we may read his being.  --Locke.

   6. To cut out, bend, or indent, as paper, sheet metal, etc.,
      into various forms, by a blow or suddenly applied pressure
      with a stamp or die, etc.; to mint; to coin.

   7. To put a stamp on, as for postage; as, to stamp a letter;
      to stamp a legal document.

   {To stamp out}, to put an end to by sudden and energetic
      action; to extinguish; as, to stamp out a rebellion.

Source : WordNet®

stamped
     adj : marked with the impression of a seal