From The Collaborative International Dictionary of English v.0.48 [gcide]: Dam \Dam\, v. t. [imp. & p. p. Dammed (d[a^]md); 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. [1913 Webster] I'll have the current in this place dammed up. --Shak. [1913 Webster] A weight of earth that dams in the water. --Mortimer. [1913 Webster] 2. To shut up; to stop up; to close; to restrain. [1913 Webster] The strait pass was dammed With dead men hurt behind, and cowards. --Shak. [1913 Webster] To dam out, to keep out by means of a dam. [1913 Webster]