noun
(countable) A round (cylindrical) vessel, such as a cask, of greater length than breadth, and bulging in the middle, made of staves bound with hoops, and having flat ends (heads). The word is sometimes applied to a similar cylindrical container made of metal, usually called a drum.
The quantity which constitutes a full barrel: the volume or weight this represents varies by local law and custom.
A solid drum, or a hollow cylinder or case
A metallic tube, as of a gun, from which a projectile is discharged.
(automotive) A venturi (in carburetion).
(television) A ceiling-mounted tube from which lights are suspended.
(archaic) Any tube.
(zoology) The hollow basal part of a feather.
(music) The part of a clarinet which connects the mouthpiece and upper joint, and resembles a barrel.
(surfing) A wave that breaks with a hollow compartment.
(US, specifically New England) A waste receptacle.
The ribs and belly of a horse or pony.
(obsolete) A jar.
(biology) Any of the dark-staining regions in the somatosensory cortex of rodents, etc., where somatosensory inputs from the contralateral side of the body come in from the thalamus.
(baseball) A statistic derived from launch angle and exit velocity of a ball hit in play.
verb
(transitive) To put or to pack in a barrel or barrels.
(intransitive) To move quickly or in an uncontrolled manner.
(intransitive) To assume the shape of a barrel; specifically, of the image on a computer display, television, etc., to exhibit barrel distortion, where the sides bulge outwards.