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.
2. The quantity which constitutes a full barrel. This varies for different articles and also in different places for the same article, being regulated by custom or by law. A barrel of wine is 31 1/2 gallons; a barrel of flour is 196 pounds.
3. A solid drum, or a hollow cylinder or case; as, 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.
5. A jar.
6. (Science: zoology) The hollow basal part of a feather.
(Science: anatomy) barrel bulk, the tympanum, or tympanic cavity. Barrel organ, an instrument for producing music by the action of a revolving cylinder. Barrel vault. See vault.
Origin: oe. Barel, f. Baril, prob. Fr. Barre bar. Cf. Barricade.