Raise an attempted robbery (4,2)
I believe the answer is:
This clue is a double definition.
'raise' is the first definition.
'an attempted robbery' is the second definition.
(eg a hold-up at a bank)
(Other definitions for hold up that I've seen before include "Delay" , "lift" , "Survive" , "Support by arms - threaten by arms" , "Stop and rob" .)