at one fell swoop

A single operation, often a violent one. This term was coined by Shakespeare, who used the metaphor of a hell-kite (probably a vulture) killing chickens for the murder of Macduff ’s wife and children: “Oh, Hell-Kite! All? What, all my pretty chickens and their dam at one fell swoop?” (Macbeth, 4.3). The adjective fell was Old English for “fierce” or “savage.”