barrel (n.) Look up barrel at Dictionary.com
c.1300, from Old French baril (12c.) "barrel, cask, vat," with cognates in all Romance languages (e.g. 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.