Tandem /(tăn"dĕm)/

Tan·dem

Tandem

adv. & a.
  1. One after another; -- said especially of horses harnessed and driven one before another, instead of abreast.

Tandem

n.
  1. A team of horses harnessed one before the other.
  2. A tandem bicycle or other vehicle.

Phrases & Compounds
Tandem bicycle
one for two persons in which one rider sits before the other.