The short name for variant Creutzfeldt-Jakob disease — a rare and very serious brain illness in humans, connected to eating beef from cattle that had BSE, the illness the newspapers called "mad cow disease." It destroys brain tissue slowly and cannot be cured. The little v at the front matters: it means "variant," and it separates this one from ordinary CJD, an older, unrelated brain disease that appears in old people by itself and has nothing to do with beef. So vCJD is the beef-linked one, and it struck mainly young people. The word carries a whole moment in British history with it — the 1990s BSE crisis, when many countries banned British beef and people stopped eating burgers. Only a few hundred people ever developed it, but the fear was enormous, and that fear is why the abbreviation is still recognised. You meet it in news reports, health writing and rules about blood donation, never in conversation. Say it letter by letter: vee-see-jay-dee.

新型庫賈氏症（俗稱人類的狂牛症）