n. [ From Gray, a. ] 1. (Zool.) A European fish (Thymallus vulgaris), allied to the trout, but having a very broad dorsal fin; -- called also umber. It inhabits cold mountain streams, and is valued as a game fish. [ 1913 Webster ]

And here and there a lusty trout,
And here and there a grayling. Tennyson. [ 1913 Webster ]

2. (Zool.) An American fish of the genus Thymallus, having similar habits to the above; one species (T. Ontariensis), inhabits several streams in Michigan; another (T. montanus), is found in the Yellowstone region. [ 1913 Webster ]