\Shear"wa`ter\, n. [Shear + water; cf. G. wassersherer; -- so called from its running lightly along the surface of the water.] (Zo["o]l.) Any one of numerous species of long-winged oceanic birds of the genus {Puffinus} and related genera. They are allied to the petrels, but are larger. The Manx shearwater ({P. Anglorum}), the dusky shearwater ({P. obscurus}), and the greater shearwater ({P. major}), are well-known species of the North Atlantic. See {Hagdon}.