Pronunciation: (tan'dum),[key] —adv. 1. one following or behind the other: to drive horses tandem. 2. in tandem, a. in single file: They swam in tandem. b. in association or partnership.
—adj. having animals, seats, parts, etc., arranged tandem or one behind another.
—n. 1. a vehicle, as a truck, tractor, or trailer, in which a pair or pairs of axles are arranged in tandem.
2. See tandem bicycle. 3. See tandem trailer (def. 1).
4. a team of horses harnessed one behind the other.
5. a two-wheeled carriage with a high driver's seat, drawn by two or more horses so harnessed.
6. any of various mechanisms having a tandem arrangement.