A construction of wood, stone or other materials, made across a stream for the purpose of penning back the waters. This word'is used in two different senses. It properly means the work or structure, raised to obstruct the flow of the water in a river; but, by a well-settled usage, it is often applied to designate the pond of water created by this obstruction. Burnham v. Kemp-ton, 44 N. H. 89; Colwell v. Water Power Co., 19 N. J. Eq. 248; Mining Co., v. Hancock, 101 Cal. 42, 31 Pal12