Quadrille: Performance given by a team of four, six, eight or more riders, involving riding an intricate pattern to music.
Quarter Horse: Breed of horse, originating in the United States and popular for ranch work, racing and riding in all equestrian disciplines.
Quarters: The part of the horse's body from the rear of the flank to the top of the tail down to the top of the gaskin. Also called the hind quarters.
Quidding: A horse that drops partially chewed food from his mouth, because of age or dental problems, is said to be "quidding". Floating the teeth usually resolves the problem.