1) The bird renowned for its song, but a name traditionally give to cows, probably ironic.
1486 ij kye called Nightigale and Luffley, Felixkirk
1547 to John Morton one cowe called Nyghtingegaile with one quie crumble headed, Great Preston
1557 two kye the one called whytehorne and the other nyghtgaill, Methley. It can be compared with 'throstle', dealt with separately, which was a popular name for a horse. The poet John Gower linked ‘The Throstle with the nyhtingale’ in 1390.