Plenty roll into a ball? (9)
I believe the answer is:
abundance
'plenty' is the definition.
(I've seen this before)
'roll into a ball?' is the wordplay.
'roll' becomes 'bun' (synonyms).
'into' means one lot of letters goes inside another.
'ball?' becomes 'dance' (ball can mean an event for dancing).
'a'+'dance'='adance'
'bun' placed inside 'adance' is 'ABUNDANCE'.
(Other definitions for abundance that I've seen before include "Nine tricks" , "Heaps of" , "Plenty, profusion" , "Host" , "Plentiful supply" .)