the space inside the root of a tooth （牙）根管 - [countable, uncountable]
an operation that involves removing infected tissue from the space inside the root of a tooth and replacing it with a substance that will protect it （牙）根管 I've had two root canals so far. 到目前为止，我有两个根管。 I'd rather have root canal than sit through another boring meeting. 我宁愿有根管，也不愿参加另一个无聊的会议。