Green’s Dictionary of Slang

cavault v.

[Ling. Fr. cavolta, riding]

to have sexual intercourse; one of a number of words equating sex with horseriding.

implied in cavaulting school
[UK]Hotten Dict. of Modern Sl. etc.
[UK]Hotten Sl. Dict.
[UK]Farmer Vocabula Amatoria (1966) 63: Cheminer [...] To copulate; ‘to cavault’.

In compounds