What may delay robbery (4-2)
I believe the answer is:
hold-up
'robbery' is the definition.
(I know that robbery can be written as hold-up)
'what may delay' is the wordplay.
I cannot quite see how this works, but
'delay' could be 'hold' (synonyms) and 'hold' is located in the answer.
The remaining letters 'up' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for hold-up that I've seen before include "Delay or show aloft" , "Commit armed robbery or keep aloft" , "Robbery at gunpoint" , "Suspend" , "Stop and rob" .)