title_body: What is the technical name for the stopper used to seal a barrel of beer or wine?
upvoted_answer: The stopper is called a “bung”. The hole is called the bung hole.
  
  
    A bung, stopper or cork is a truncated cylindrical or conical closure to seal a container, such as a bottle, tube or barrel. Unlike a lid, which encloses a container from the outside without displacing the inner volume, a bung is partially inserted inside the container to act as a seal. - Bung (Wikipedia)
  
  
  
  
  Bung in the bunghole of a wine barrel