Something rolled out for fun (on staves) (6)
I believe the answer is:
barrel
'fun on staves' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for barrel that I've seen before include "Revolving drum" , "Liquor container" , "Cylindrical crate" , "Beer/oil container" , "Large round container as for beer" .)