QC is a high title in the British legal world. It stood for Queen’s Counsel: a barrister — a court lawyer — chosen as one of the best. After that, the lawyer wore a silk gown in court, and people still say a lawyer “takes silk.” You put the letters after the name, like Jane Smith QC. It is formal British English (and you will also see it in some countries that followed British law). You meet it in news about big court cases, not in everyday talk. Though actually, since 2022 Britain has a king, not a queen, so new appointments are King’s Counsel, written KC. Many people still say QC out of habit, and some older lawyers still use those letters. The tidy dictionary line has not quite caught up with the living title.