Cask, keg (6)
I believe the answer is:
barrel
This clue is a double definition.
'cask' is the first definition.
(synonyms)
'keg' is the second definition.
(I've seen this in another clue)
(Other definitions for barrel that I've seen before include "Large keg" , "Tube of a gun" , "Cheerful old song: 'Roll out the . . . . . .'" , "Revolving drum" , "full of laughs?" .)