bunghole

/B AH1 NG HH OW0 L/
noun
  1. 1

    A hole in a vessel, such as a cask, that may be stopped with a bung.

    โ€œPop a tap in the barrel's bung-hole so you can pour us a round of beer, innkeeper!โ€

  2. 2

    The anus.

Source: https://en.wiktionary.org/wiki/bung-hole, https://en.wiktionary.org/wiki/bunghole