What is the meaning of barrels?

noun

• A tube through which a bullet travels when a gun is fired.
  • synonyms: barrel, gun barrel
• A cylindrical container that holds liquids.
  • synonyms: barrel, cask
• A bulging cylindrical shape; hollow with flat ends.
  • synonyms: barrel, drum
• The quantity that a barrel (of any size) will hold.
  • synonyms: barrel, barrelful
• Any of various units of capacity.
  • usage: "a barrel of beer is 31 gallons and a barrel of oil is 42 gallons"
  • synonyms: barrel, bbl
• The amount that many barrels might hold.

verb

• Put in barrels.
  • synonyms: barrel