A person that excels at sales and closing deals. To have superior ability to close someone "this term was coined for sales associates" To be able to control a conversation or phone call and get the end result accomplished. This term is given to the cream of the crop in sales and typically reffers to the best of the best in sales.
Example 1.) That Michael D. Jackson is sure a king closer, he called that Potential Customer and had his credit card # in 5 minutes.
Example 2.) Out of all of the Associates at AST, Mike jackson is a king among the closers for the company
Example 3.) The scent that is put off as Michael D Jackson chokes them with his huge closers brass balls.