A bit of work on toy (6)
I believe the answer is:
dollop
'a bit' is the definition.
(thesaurus)
'work on toy' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'on' means one lot of letters go next to another.
'toy' becomes 'doll' (doll is a kind of toy).
'op' put after 'doll' is 'DOLLOP'.
'of' acts as a link.
(Other definitions for dollop that I've seen before include "Small shapeless mass" , "Large piece" , "Shapeless mass or lump" , "Shapeless mass of soft food" , "A shapeless lump of something soft, like dough" .)