manhole

/M AE1 N HH OW0 L/
noun
  1. 1

    A hole in the ground used to access the sewers or other underground vaults and installations.

  2. 2

    A hole providing access to the inside of a boiler, tank etc.

  3. 3

    A man's anus, in a sexual context.

Source: https://en.wiktionary.org/wiki/manhole