Source : Webster's Revised Unabridged Dictionary (1913)

Clamp \Clamp\ (kl[a^]mp), v. t. [imp. & p. p. {Clamped}
   (kl[a^]mt; 215) p. pr. & vb. n. {Clamping}.]
   1. To fasten with a clamp or clamps; to apply a clamp to; to
      place in a clamp.

   2. To cover, as vegetables, with earth. [Eng.]

Clamp \Clamp\, n. [Prob. an imitative word. Cf. {Clank}.]
   A heavy footstep; a tramp.

Clamp \Clamp\, v. i.
   To tread heavily or clumsily; to clump.

         The policeman with clamping feet.        --Thackeray.

Clamp \Clamp\ (kl[a^]mp), n. [Cf. LG. & D. klamp, Dan. klampe,
   also D. klampen to fasten, clasp. Cf. {Clamber}, {Cramp}.]
   1. Something rigid that holds fast or binds things together;
      a piece of wood or metal, used to hold two or more pieces
      together.

   2.
      (a) An instrument with a screw or screws by which work is
          held in its place or two parts are temporarily held
          together.
      (b) (Joinery) A piece of wood placed across another, or
          inserted into another, to bind or strengthen.

   3. One of a pair of movable pieces of lead, or other soft
      material, to cover the jaws of a vise and enable it to
      grasp without bruising.

   4. (Shipbuilding) A thick plank on the inner part of a ship's
      side, used to sustain the ends of beams.

   5. A mass of bricks heaped up to be burned; or of ore for
      roasting, or of coal for coking.

   6. A mollusk. See {Clam}. [Obs.]

   {Clamp nails}, nails used to fasten on clamps in ships.

Source : WordNet®

clamp
     n : a device (used by carpenters) that holds things firmly
         together
     v 1: fasten or fix with a clamp; "clamp the chair together until
          the glue has hardened"
     2: impose or inflict forcefully; "The military government
        clamped a curfew onto the capital"