A prebuttal is a reply to an attack that has not even been made yet. A politician, or someone speaking for them, stands up and says “this criticism is false or unfair” — before the other side has said it out loud. The word is a joke-shaped blend, used in politics and news, not in the kitchen. It became common in American political talk in the early 2000s, and it still sounds like media slang: a little clever, a little weary. Though actually, the idea is older than the word; people have always tried to kill a story before it lands. A prebuttal is not a proof, and it is not a normal defence after you have been accused. It is defence fired early, sometimes so early that listeners feel they are being steered. You would not put it in a school essay unless you were writing about politics on purpose. There is no widely used everyday verb; people say “issue a prebuttal” or “prebut” only in the same newsy circle.

預防性反駁、預先駁斥。台灣新聞較常說「預防性澄清」，那是同一個政治動作，只是用字比較不像新造的英文玩笑。