bbl

noun

1. 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.