Fielder in error (4)
I believe the answer is:
slip
I believe this is a double definition.
'fielder' is the first definition.
(slip is a cricket fielding position)
'error' is the second definition.
(slip is a kind of error)
'in' acts as a link.
(Other definitions for slip that I've seen before include "Lose footing as on banana skin" , "Error; watered clay" , "Glide; petticoat" , "shift" , "have an accident" .)