CJK Character 痤

It names a small swelling or boil; modern 痤疮 means acne. The left part 疒 marks illness, while 坐 gives the sound cuó. Its disease-name use reaches the pre-Han Zhuangzi tradition; a later dictionary defines it as small swelling and notes a livestock-disease sense.

Older medical writing grouped 痤 with 癤, 癰, and 疽, sometimes by size or course; the exact boundaries varied. In modern Chinese usage, 痤 mainly survives inside 痤疮, while everyday speech also says 青春痘 or 痘痘. Alone, it sounds formal or classical.