manhole
noun [ C ] uk/ˈmæn.həʊl/ us/ˈmæn.hoʊl/
（地下管线或下水道供人出入检修的）人孔，检修孔，检查井
a covered opening in a road that a worker can enter in order to reach underground pipes, wires, or drains that need to be examined or repaired
a manhole cover 检查井井盖