Emily Dickinson Lexicon

DAM, v.t. [Sax. demman; G. dämmen; D. dammen; Dan. dæmmer; Ch. טום to stop, to shut; Heb. and Ch. אטם, Ar. أَطَمَ atama, to stop or shut. Qu. Ch. סטם, Ar. سَطَمَ satama, id. This is the root of dumb. See Class Dm, No. 17, 18, 23, 39.]

1. To make a dam, or to stop a stream of water by a bank of earth, or by any other work; to confine or shut in water. It is common to use, after the verb, in, up, or out; as, to dam in, or to dam up, the water, and to dam out is to prevent water from entering.
2. To confine or restrain from escaping; to shut in; used by Shakespeare of fire, and by Milton of light.