barrel (n.) Look up barrel at Dictionary.com
c.1300, from Old French baril (12c.) "barrel, cask, vat," with cognates in all Romance languages (such as Italian barile, Spanish barril), but origin uncertain; perhaps from Gaulish, perhaps somehow related to bar (n.1). Meaning "metal tube of a gun" is from 1640s. Barrel roll in aeronautics is from 1927.
barrel (v.) Look up barrel at Dictionary.com
mid-15c., "to put in barrels," from barrel (n.). Meaning "to move quickly" is 1930, American English slang, perhaps suggestive of a rolling barrel. Related: Barreled; barreling.