The term 'Big Barrel' can be described by two crossword solutions: CASK (4 letters) and DRUM (4 letters). A CASK is a large barrel-shaped container made of wood or metal, typically used for storing liquids such as wine or beer. A DRUM is a cylindrical container used to store or transport goods, usually made of metal or plastic. Both CASK and DRUM are commonly used to store large amounts of liquid, making them suitable for the term 'Big Barrel'.