Work over, repeat in error (7)
I believe the answer is:
operate
'work' is the definition.
('operate' can be a synonym of 'work')
'over repeat in error' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'in error' is an anagram indicator.
'repeat' anagrammed gives 'perate'.
'o'+'perate'='OPERATE'
(Other definitions for operate that I've seen before include "Make function" , "Eat rope (anag.)" , "Work - perform surgery" , "Make to work" , "effect" .)