one fell swoop

This idiom was first popularized (or perhaps first coined) by Shakespeare in Macbeth in 1605. Macduff had just heard that all his family and servants had been killed and said:

All my pretty ones?
Did you say all? O hell-kite! All?
What, all my pretty chickens and their dam
At one fell swoop?


kite A kite is a hunting bird that swoops down and seizes its prey. The Oxford English Dictionary gives us an older meaning for the word "fell" as "fierce, savage; cruel, ruthless; dreadful, terrible," and lists it as the original root of our word "felon."

So in its original meaning, the phrase conveyed a note of suddenness and savagery that we don't necessarily apply to it today.