From Longman Dictionary of Contemporary Englishgunslingergun‧sling‧er /ˈɡʌnˌslɪŋə $ -ər/ noun [countable] American English informal SHOOTsomeone who is very skilful at using guns, especially a criminal
Examples from the Corpus
gunslinger• He was an information officer, not a gunslinger versed in controlling the tension of a shoot-out.• First he began to shy away from the crowd of young street thug arsonist gunslingers.• A peerless champion of his own era, he had been reduced to an ineffectual has-been by the modern gunslingers.• It wanted to go from being seen as a bunch of gunslingers to a more professional business approach.• Where were the saloons and the gunslingers and the professional card sharks?• Creed, the gunslinger, had been faster, though. 