Definition of "barrel" []

• A large cylindrical container, usually made of staves bound together with hoops, with a flat top and bottom of equal diameter. (noun)
• The quantity that a barrel with a given or standard capacity will hold. (noun)
• 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. (noun)
• The cylindrical part or hollow shaft of any of various mechanisms, as: (noun)
• The metal, cylindrical part of a firearm through which the bullet travels. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The 21 months this wine spent in barrel is much more apparent, almost overwhelming at this stage in the wine's development."
• "The main barrel is made from metal, and the handle and stock is mostly card, dense card with a layer of corrugated."
• "The term barrel of oil equivalent ( "boe") may be misleading, particularly if used in isolation."