Loach \Loach\, n. [OE. loche, F. loche.] (Zo["o]l.) Any one of several small, fresh-water, cyprinoid fishes of the genera {Cobitis}, {Nemachilus}, and allied genera, having six or more barbules around the mouth. They are found in Europe and Asia. The common European species ({N. barbatulus}) is used as a food fish.