Surface channel for conveying water.

A manmade water channel usually built to supply water to a mill.

(Leet) An artificial waterway, used to divert water for use in a mill, etc.

A leat (also spelled lete) is the name, common in the south and west of England, for a man-made watercourse, or makeshift aqueduct, often an artificial channel which supplies water to a watermill or its mill pond, collecting water from upstream of the mill so that the natural level of the driving water is above the level of the stream at the mill. Other names for the same thing include fleam (probably a leat supplying water to a mill that did not have a millpool). In parts of northern England, for example around Sheffield the equivalent word is goit.