Tandem \Tan"dem\, n. A team of horses harnessed one before the other. ``He drove tandems.'' --Thackeray.

Tandem engine, a compound steam engine having two or more steam cylinders in the same axis, close to one another.

Tandem bicycle or tricycle, one for two persons in which one rider sits before the other.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Tricycle \Tri"cy*cle\, n. [Pref. tri- + cycle as inbicycle.]

A three-wheeled velocipede. See Illust. under Velocipede. Cf. Bicycle.

Source: Webster's Revised Unabridged Dictionary (1913)