A manhole is an opening in a road, pavement, or floor, usually closed by a heavy lid. Under the lid are pipes, wires, or a tunnel, and a worker climbs down to look at them or fix them. The lid is a manhole cover — often round, so it cannot fall through the hole. The man here is the old general word for a person, not “male only,” though actually some cities now write maintenance hole on official papers because manhole can sound as if only men do the job. In ordinary speech, people still say manhole. You see it on warning signs, and in the news when a cover is missing and the hole is dangerous.

人孔（蓋）。台灣說人孔、人孔蓋；中國大陸較常說窨井、檢查井。