a cylindrical wooden container with slightly bulging sides made of staves hooped together, and with flat, parallel ends.
2.
the quantity that such a vessel of some standard size can hold: for most liquids, 311/2 U.S. gallons (119 L); for petroleum, 42 U.S. gallons (159 L); for dry materials, 105 U.S. dry quarts (115 L). Abbreviation:bbl
3.
any large quantity: a barrel of fun.
4.
any container, case, or part similar to a wooden barrel in form.
5.
Ordnance. the tube of a gun.
6.
Machinery. the chamber of a pump in which the piston works.
7.
a drum turning on a shaft, as in a weight-driven clock.
8.
Horology. the cylindrical case in a watch or clock within which the mainspring is coiled.
9.
OrnithologyObsolete. a calamus or quill.
10.
the trunk of a quadruped, esp. of a horse, cow, etc.
11.
Nautical. the main portion of a capstan, about which the rope winds, between the drumhead at the top and the pawl rim at the bottom.
12.
a rotating horizontal cylinder in which manufactured objects are coated or polished by tumbling in a suitable substance.
13.
any structure having the form of a barrel vault.
14.
Also called throat.Automotive. a passageway in a carburetor that has the shape of a Venturi tube.
–verb (used with object)
15.
to put or pack in a barrel or barrels.
16.
to finish (metal parts) by tumbling in a barrel.
17.
Informal. to force to go or proceed at high speed: He barreled his car through the dense traffic.
–verb (used without object)
18.
Informal. to travel or drive very fast: to barrel along the highway.
—Idiom
19.
over a barrel, Informal. in a helpless, weak, or awkward position; unable to act: They really had us over a barrel when they foreclosed the mortgage.
Origin: 1250–1300; ME barell < AF baril, OF barril < VL *barrīculum, equiv. to *barrīc(a), perh. deriv. of LL barrabar1+ L -ulum-ule; cf. ML (ca. 800) barriclus small cask
A large cylindrical container, usually made of staves bound together with hoops, with a flat top and bottom of equal diameter.
The quantity that a barrel with a given or standard capacity will hold.
Abbr. bar. or bbl. or bl. Any of various units of volume or capacity. In the U.S. Customary System it varies, as a liquid measure, from 31 to 42 gallons (120 to 159 liters) as established by law or usage. See Table at measurement.
The cylindrical part or hollow shaft of any of various mechanisms, as:
The metal, cylindrical part of a firearm through which the bullet travels.
A cylinder that contains a movable piston.
The drum of a capstan.
The cylinder within the mechanism of a timepiece that contains the mainspring.
The trunk of a quadruped animal, such as a horse or cow.
Informal A large quantity: a barrel of fun.
Slang An act or instance of moving rapidly, often recklessly, in a motor vehicle.
adj. Likened to a barrel, as in shape: a barrel chest; barrel hips. v.
bar·reled or bar·relled, bar·rel·ing or bar·rel·ling, bar·rels
v.
tr. To put or pack in a barrel. v.
intr.Slang To move at a high speed or rate of progress: "That the European Union barreled ahead was not surprising"(Richard W. Stevenson).
[bar-uh
l] 
noun, verb, -reled, -rel⋅ing or (especially British