manhole

noun

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

   “The king had scarce ceased to writhe, When hate gave a terrible laugh, Like a manhole opened to Hell.”

2. A hole providing access to the inside of a boiler, tank etc.
3. (informal)The anus of man, in a sexual context.

   “For quotations using this term, see Citations:manhole.”

4. The vulva or vagina of a trans man.