(historical) A Roman racing chariot drawn by four horses abreast.
In the Vatican Library is a vase of terra cotta, on whose upper part we see delineated the sun and moon, in a quadriga, which proceeds forward [travels, voyages, fulfils its course] upon a ship. […] Both these deities stand in a quadriga, which indeed is the vehicle proper to the sun, insomuch that the Rhodians every year threw into the sea a quadriga, dedicated to this divinity.
On another denarius we see Victory holding a wreath and driving a quadriga […]
(historical) A team of four horses, or sometimes other animals, especially as used in chariot racing.