Carol collects stuff for a bit (10)
I believe the answer is:
smattering
'a bit' is the definition.
(I know that bit can be written as smattering)
'carol collects stuff' is the wordplay.
'carol' becomes 'sing' (carol can mean to sing carols).
'collects' means one lot of letters goes inside another.
'stuff' becomes 'matter' (I've seen this in other clues).
'sing' placed around 'matter' is 'SMATTERING'.
'for' is the link.
(Other definitions for smattering that I've seen before include "Hint" , "little knowledge" , "Dash" , "Taste" , "Little bit" .)