Green’s Dictionary of Slang

1. having sexual intercourse, thus jockeying trade, prostitution.

c.1780

Entire New List of the Sporting Ladies [broadsheet] A bonny parcel of Lilly-white Frows [...] are now determined to try their Fortunes in the Jockeying Trade.

2. racing carriages along the streets of London.

1909

J. Ware Passing Eng. of the Victorian Era 160/1: Jockeying (London Streets, 19 cent.) Vehicular racing.