The Collaborative International Dictionary of English v.0.48:
Tricycle \Tri"cy*cle\, n. [Pref. tri- + cycle as inbicycle.] A three-wheeled velocipede. See Illust. under Velocipede. Cf. Bicycle. [1913 Webster]WordNet (r) 3.0 (2006):
tricycle n 1: a vehicle with three wheels that is moved by foot pedals [syn: tricycle, trike, velocipede]