barrelbar·rel /ˈbærəl/ noun [countableC]1TRANSPORTa large round container with a flat top and bottom, used for storing and carrying liquids such as oil and beerbarrels of beer
2an amount of a liquid contained in a barrel, used as unit of measurement, especially in the oil industryThere were fears that the price of crude would drop as far as $15 a barrel.
The country produces more than 650,000 barrels per day of crude oil.
→ see also pork barrel