What is one fell swoop?

The phrase "one fell swoop" means to accomplish something or to have something happen all at once, in a single and often swift action. The term is believed to have originated from William Shakespeare’s play "Macbeth," written in the early 17th century. In Act 4, Scene 3, Macduff learns about the tragic and sudden murder of his entire family, and uses the phrase "What, all my pretty chickens and their dam at one fell swoop?" The word "fell" in this context implies something fierce, cruel, or deadly, suggesting a sudden and devastating action. Over time, the phrase has become commonly used in English to describe any situation where multiple things are done or achieved simultaneously.