kelpie

{ }, n.; pl. Kelpies [ Cf. Gael. cailpeach, calpach, colpach, a heifer, steer, colt, colpa a cow or horse. ] (Scotch Myth.) An imaginary spirit of the waters, horselike in form, vulgarly believed to warn, by preternatural noises and lights, those who are to be drowned. Jamieson. [ 1913 Webster ]