Related Clues:

• Cab client
• Thoroughbred irritated over what it's carrying
• Jockey or bicyclist
• Knight for one rook and plan sacrificing a queen
• What a hitchhiker aspires to be
• Someone pillaging downs a horseman
• Girlfriend dismisses fling with jockey
• Proviso added to an agreement
• Train patron
• Train passenger
• One who's up?
• Mounted guard perhaps freed American casualty
• Old US president protected by British motorcyclist
• Break the ice dismissing Hecate - presumably she's a member of the Hells Angels?
• Horseman, e.g.