Hammer or screwdriver (4)
I believe the answer is:
tool
I believe this is a double definition.
'hammer' is the first definition.
(I've seen this in another clue)
'screwdriver' is the second definition.
(thesaurus)
(Other definitions for tool that I've seen before include "Practical implement" , "Pawn" , "Drive motor skilfully" , "Appliance" , "Person exploited" .)