The Collaborative International Dictionary of English v.0.48:
Riding \Rid"ing\, a.
1. Employed to travel; traveling; as, a riding clerk. "One
riding apparitor." --Ayliffe.
2. Used for riding on; as, a riding horse.
3. Used for riding, or when riding; devoted to riding; as, a
riding whip; a riding habit; a riding day.
(a) A clerk who traveled for a commercial house. [Obs.
(b) One of the "six clerks" formerly attached to the
English Court of Chancery.
(a) A hood formerly worn by women when riding.
(b) A kind of cloak with a hood.
Riding master, an instructor in horsemanship.
Riding rhyme (Pros.), the meter of five accents, with
couplet rhyme; -- probably so called from the mounted
pilgrims described in the Canterbury Tales. --Dr. Guest.
Riding school, a school or place where the art of riding is