Could he start robbing some guests? (5)
I believe the answer is:
rogue
'could he start robbing some guests?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'could he' is the wordplay.
I cannot quite see how this works, but
'he' could be 'rog' and 'rog' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rogue that I've seen before include "Scallywag" , "Baddy" , "Villain - freak" , "Prankster" , "Diverging from type" .)