at/in one fell swoop

at one fell swoop

All at once, with a single decisive or powerful action. When the economy crashed, thousands lost their jobs, their homes, and their pensions at one fell swoop.
See also: fell, one, swoop

in one fell swoop

All at once, with a single decisive or powerful action. When the economy crashed, thousands lost their jobs, their homes, and their pensions in one fell swoop.
See also: fell, one, swoop

at one fell swoop

 and in one fell swoop
Fig. in a single incident; as a single event. (This phrase preserves the old word fell, meaning "terrible" or "deadly.") The party guests ate up all the snacks at one fell swoop. When the stock market crashed, many large fortunes were wiped out in one fell swoop.
See also: fell, one, swoop

in (or at) one fell swoop

all in one go.
This expression comes from Macduff's appalled reaction to the murder of his wife and children in Shakespeare's Macbeth: ‘Oh hell-kite!…All my pretty chickens, and their dam At one fell swoop?’
See also: fell, one, swoop

at/in one fell ˈswoop

with a single action or movement; all at the same time: Only a foolish politician would promise to lower the rate of inflation and reduce unemployment at one fell swoop.
See also: fell, one, swoop