Old English cwellan 'kill', of Germanic origin; related to Dutch kwellen and German quälen.

• kill from Middle English:

  Like kick, kill is of unknown origin, although it may be related to quell which meant ‘kill’ in Old English. To be in at the kill is to be present at or benefit from the successful conclusion of an enterprise. The image comes from the idea of the climax of a hunt. In 1814 the future William IV, contemplating the defeat of Napoleon, wrote triumphantly, ‘The game is up with Bonaparte, and I shall be in at the kill.’ Medicine in the 18th century was a risky business, hence kill or cure. Achieving two goals at once is always an attractive thought. Since the 17th century one way of expressing the idea has been to refer to the hope of bird scarers in fields that they can kill two birds with one stone. To kill someone with kindness dates back to the mid 16th century, and appeared in the title of a play of the early 17th century, Thomas Heywood's A Woman Killed with Kindness. The film The Killing Fields, released in 1984, dealt with the horrific events in Cambodia during the Khmer Rouge dictatorship of 1975–9, when thousands of people were executed in killing fields and many more died of starvation. The term is first recorded in the early years of the 20th century and is a variation of killing ground, a place where seals were slaughtered.