Sell battered fish over time (5)
I believe the answer is:
shift
'sell' is the definition.
(shift can mean to get rid of or sell)
'battered fish over time' is the wordplay.
'battered' indicates anagramming the letters.
'over' is a charade indicator (letters next to each other) (in a down clue, some letters go over others).
'time' becomes 't' (abbreviation).
'fish' anagrammed gives 'shif'.
'shif'+'t'='SHIFT'
(Other definitions for shift that I've seen before include "hours of work" , "Dislodge" , "eat quickly" , "Alter" , "Change (gear); dress" .)