bar·rel / ˈbarəl/ • n. 1. a cylindrical container bulging out in the middle, traditionally made of wooden staves with metal hoops around them. ∎ such a container together with its contents: a barrel of beer. ∎ a measure of capacity used for oil and beer usually equal to 42 U.S. gallons (roughly 192 liters).2. a tube forming part of an object such as a gun or a pen.3. the belly and loins of a four-legged animal such as a horse.• v. (-reled, -rel·ing; Brit. -relled, -rel·ling) 1. [intr.] inf. drive or move fast, often heedless of surroundings or conditions: we barreled across the Everglades barreling along the Ventura freeway.2. [tr.] put into a barrel or barrels.PHRASES: a barrel of laughs inf. a source of fun or amusement: life is not exactly a barrel of laughs at the moment.over a barrel inf. in a helpless position; at someone's mercy.with both barrels inf. with unrestrained force or emotion.
over a barrel in a helpless position, at someone's mercy. Perhaps referring to the condition of a person who has been rescued from drowning and is placed over a barrel to clear the lungs of water.