1) Amount of fun 2) Containers 3) Crude measurements 4) Groups of monkeys 5) Hogsheads 6) Items in a rodeo race 7) Kegs 8) Large indefinite amount 9) Large indefinite quantity 10) Large wine containers 11) Lots 12) Oil containers 13) Oil units 14) Opec units 15) Persian Gulf measurements 16) Pickle tubs Found on https://www.crosswordclues.com/clue/barrels
Volume measurement of liquid, typically oil, equal to 42 US gallons or 35 imperial gallons. Barrels... <a target=_blank href='http://www.finance-glossary.com/terms/barrels.htm?id=12673&ginPtrCode=00000&PopupMode=false' title='Read full definition of barrels'>more</a>
Found on http://www.finance-glossary.com/pages/home.htm