/kes"treuhl/ , n.
1. a common small falcon, Falco tinnunculus, of northern parts of the Eastern Hemisphere, notable for hovering in the air with its head to the wind.
2. any of several related small falcons, as the American kestrel, F. sparverius.
[ 1400-50; late ME castrell quercerelle, metathetic var. of CRECERELLE, of disputed orig. ]