jump-out
n.— «One week after Tyshaun’s slaying, narcotics officers made a bust at a house across the street. As officers approached, the three children left unattended there shouted a warning to their mother: “The jump-outs are here.”» —“Battfield on Beat 252” by Lara Becker Democrat and Chronicle (Rochester, N.Y.) Aug. 12, 2001. (source: Double-Tongued Dictionary)