Sailor bringing deserter from the East (3)
I believe the answer is:
'sailor' is the definition.
(slang term for a sailor)
'deserter from the east' is the wordplay.
'deserter' becomes 'rat' (both can mean a traitor).
'from the east' shows that the letters should be reversed in order (on a map from right to left).
'rat' reversed gives 'TAR'.
'bringing' acts as a link.
(Other definitions for tar that I've seen before include "Jack ..., British sailor" , "Sticky substance - seaman" , "Liquid from wood, coal" , "Dark viscous stuff" , "Sticky black stuff" .)