rider
noun
1
a visible, aggressive member of a gang US, 2001.
2
a police officer US, 2003.
3
5 kg of heroin supplied free with a 100 kg shipment of cocaine UK, 2002.
4
a cheater. From the phrase RIDE A PONY (to cheat on a test) US, 1959.
5
in trucking, a flat tyre on a set of dual tyres US, 1971