Dangerous guns a fellow's carrying (6)
I believe the answer is:
unsafe
'dangerous' is the definition.
('unsafe' can be a synonym of 'dangerous')
'guns a fellow's carrying' is the wordplay.
'carrying' indicates the answer is hidden within the clue.
'UNSAFE' can be found hidden inside 'guns a fellows'.
(Other definitions for unsafe that I've seen before include "Risky - inadequately evidenced" , "Not reliable, dangerous - perhaps a legal conviction" , "giving no protection" , "Hazardous" , "Dangerous, insecure" .)