Stinger? (5)
(Other definitions for barb that I've seen before include "Hurtful comment" , "Twisted point of hook" , "part of a habit" , "Stage whispers" , "Insult" .)
(Other definitions for narco that I've seen before include "Member of US drugs squad" , "American drug agent" , "Drug trafficker" , "Drugs agent (US slang)" .)