airlocks

/EH1 R L AO0 K S/
noun
  1. 1

    A small amount of air in a pipe that stops liquid flowing through it

noun
  1. 1

    A sealed, airtight chamber, such as in a manned spacecraft or submarine, used to provide access to and from the sealed area without allowing air out or water in.

Source: https://en.wiktionary.org/wiki/air%20lock, https://en.wiktionary.org/wiki/airlock, https://en.wiktionary.org/wiki/airlocks