Barrier to dodgy dealer (5)
I believe the answer is:
fence
This clue is a double definition.
'barrier' is the first definition.
(I know that fence is a type of barrier)
'dodgy dealer' is the second definition.
(trader of stolen goods)
'to' is the link.
(Other definitions for fence that I've seen before include "Palisade" , "use offensive weapons" , "railings" , "Guard" , "may be 21 down [CLEARED]" .)