The Collaborative International Dictionary of English v.0.48:

Stamp \Stamp\ (st[a^]mp) v. t. [imp. & p. p. Stamped
   (st[a^]mt; 215); p. pr. & vb. n. Stamping.] [OE. stampen;
   akin to LG. & D. stampen, G. stampfen, OHG. stampf[=o]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.
      [1913 Webster]

            He frets, he fumes, he stares, he stamps the ground.
                                                  --Dryden.
      [1913 Webster]

   2. To bring down (the foot) forcibly on the ground or floor;
      as, he stamped his foot with rage.
      [1913 Webster]

   3. To crush; to pulverize; specifically (Metal.), to crush by
      the blow of a heavy stamp, as ore in a mill.
      [1913 Webster]

            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.
      [1913 Webster]

   4. To impress with some mark or figure; as, to stamp a plate
      with arms or initials.
      [1913 Webster]

   5. Fig.: To impress; to imprint; to fix deeply; as, to stamp
      virtuous principles on the heart.
      [1913 Webster]

            God . . . has stamped no original characters on our
            minds wherein we may read his being.  --Locke.
      [1913 Webster]

   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.
      [1913 Webster]

   7. To put a stamp on, as for postage; as, to stamp a letter;
      to stamp a legal document.
      [1913 Webster]

   To stamp out, to put an end to by sudden and energetic
      action; to extinguish; as, to stamp out a rebellion.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "stamped":
   accepted, acknowledged, admitted, affirmed, allowed, approved,
   authenticated, avowed, carved, certified, conceded, confessed,
   confirmed, countersigned, creased, cut, enchased, endorsed,
   engraved, furrowed, glyphic, granted, graved, graven, grooved,
   impressed, imprinted, incised, inscribed, insculptured, lined,
   marked, notarized, printed, professed, ratified, received,
   recognized, sculptured, sealed, signed, sworn and affirmed,
   sworn to, tooled, underwritten, validated, warranted