Bit of fish I dropped over (8)
I believe the answer is:
finished
'over' is the definition.
(similar in meaning)
'bit of fish i dropped' is the wordplay.
'bit of fish' becomes 'fin' (fish have fins).
'dropped' becomes 'shed' ('shed' can be a synonym of 'drop').
'fin'+'i'+'shed'='FINISHED'
(Other definitions for finished that I've seen before include "dressed" , "exhausted" , "Done, over, ended" , "wrapped up" , "Ended. completed" .)