one fell swoop

A single and rapid act. “Fell” comes from an Old English word for frightful and “swoop” describes the way hawks and other birds of prey drop out of the sky to capture their victims. Accordingly, something that is done “in one fell swoop,” whether or not it is awful, happens with no hesitation. Shakespeare coined the phrase in Macbeth, where the character Macduff laments the murders of his wife and children with “What, all my pretty chick- ens and their dam / At one fell swoop?”