Source : Webster's Revised Unabridged Dictionary (1913)

Dam \Dam\, v. t. [imp. & p. p. {Dammed}; p. pr. & vb. n.
   {Damming}.]
   1. To obstruct or restrain the flow of, by a dam; to confine
      by constructing a dam, as a stream of water; -- generally
      used with in or up.

            I'll have the current in this place dammed up.
                                                  --Shak.

            A weight of earth that dams in the water.
                                                  --Mortimer.

   2. To shut up; to stop up; to close; to restrain.

            The strait pass was dammed With dead men hurt
            behind, and cowards.                  --Shak.

   {To dam out}, to keep out by means of a dam.