A round vessel or cask, of greater length than breadth, and bulging in the middle, made of staves bound with hoops, and having flat ends or heads. Sometimes applied to a similar cylindrical container made of metal, usually called a drum.
a cracker barrel
2
The quantity which constitutes a full barrel: the volume or weight this represents varies by local law and custom.
3
A solid drum, or a hollow cylinder or case
the barrel of a windlass; the barrel of a watch, within which the spring is coiled.
4
A metallic tube, as of a gun, from which a projectile is discharged.