What is the meaning of "Yu" in the ancient six arts "Li, Yue, Shooting, Yu, Shu and Shu"?

Driving skill

Ceremony: Etiquette (similar to moral education today). Five rites, auspicious, fierce, guest, army and Jia also. ; Le: Music. Six kinds of music: Cloud Gate, Daxian, Dashao, Daxia, Daxie and Dawu. ; Shooting: archery technique. The skill of driving a carriage.