Fluke (flūk), n. [Cf. AS. flōc a kind of flatfish, Icel. flōki a kind of halibut.] 1. (Zoöl.) The European flounder. See Flounder. [Written also fleuk, flook, and flowk].
2. (Zoöl.) A parasitic trematode worm of several species, having a flat, lanceolate body and two suckers. Two species (Fasciola hepatica and Distoma lanceolatum) are found in the livers of sheep, and produce the disease called rot.