Nightingale (?), n. [OE. nihtegale,nightingale, AS. nihtegale; niht night + galan to sing, akin to E. yell; cf. D. nachtegaal, OS. nahtigala, OHG. nahtigala, G. nachtigall, Sw. näktergal, Dan. nattergal. See Night, and Yell.] 1. (Zoöl.) A small, plain, brown and gray European song bird (Luscinia megarhynchos syn. Luscinia luscinia). It sings at night, and is celebrated for the sweetness of its song.
[1913 Webster]

2. (Zoöl.) A larger species (Lucinia philomela), of Eastern Europe, having similar habits; the thrush nightingale. The name is also applied to other allied species.
[1913 Webster]

Mock nightingale. (Zoöl.) See Blackcap, n., 1 (a).
[1913 Webster]