an opening, often with a cover, through which a person can enter a sewer, conduit, ship's tank, etc. for repair work or inspection
A hole, usually with a cover, through which a person may enter a sewer, boiler, drain, or similar structure.
- A hole in the ground used to access the sewers or other underground vaults and installations.
- In contexts such as government documents where anything that might be perceived as sexist is avoided, this has mostly been replaced by maintenance hole