one fell swoop, in

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in one fell swoop

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Idioms and Phrases

Also at one fell swoop . All at once, in a single action, as in This law has lifted all the controls on cable TV in one fell swoop . This term was used and probably invented by Shakespeare in Macbeth (4:3), where the playwright likens the murder of Macduff's wife and children to a hawk swooping down on defenseless prey. Although fell here means “cruel” or “ruthless,” this meaning has been lost in the current idiom, where it now signifies “sudden.”