bug
n.— «Now that Ms. Studart is no longer an apprentice, her prospects for rides are unclear, especially with more experienced jockeys coming to New York for the summer season. Trainers tend to favor apprentices—nicknamed “bugs” for the asterisks that follow their names on programs—because they get to carry less weight.» —“A Long Way From Home, Moving at Great Speed” in Cara Buckley New York Times Mar. 27, 2009. (source: Double-Tongued Dictionary)