autograt
n.— «While most restaurants already charge an automatic service fee for large parties, at least one restaurant began the practice of charging an automatic 20 percent gratuity, or “autograt,” as it is sometimes called, on every check.» —“Don’t forget to tip the wait staff” by Betsy Schiffman in New York AP Sept. 12, 2006. (source: Double-Tongued Dictionary)