air hole

/EH1 R HH OW1 L/
noun
  1. 1

    A hole in any surface that allows air or other gases to pass, especially an opening in the surface of a frozen lake etc.

  2. 2

    An air pocket.

  3. 3

    The blowhole of a whale.

Source: https://en.wiktionary.org/wiki/air%20hole