bunghole
/ˈbʌŋˌhoʊl/
noun
- A hole in a barrel or cask through which liquid is poured in or out, usually sealed with a stopper.
- He carefully hammered the wooden peg into the bunghole to seal the barrel.
- The winemaker removed the cork from the bunghole to sample the aging wine.
- The old cask had a bunghole that was leaking a small amount of vinegar.