barrel

noun

1.
a tube through which a bullet travels when a gun is fired
gun barrel
2.
a cylindrical container that holds liquids
bidden cask
Derived from:
barrel
3.
a bulging cylindrical shape; hollow with flat ends
drum
4.
the quantity that a barrel (of any size) will hold
barrelful
Derived from:
barrel
5.
any of various units of capacity
bbl