The Collaborative International Dictionary of English v.0.48:
motorless \motorless\ adj. having no motor. Opposite of motorized. Syn: unmotorized. [WordNet 1.5]WordNet (r) 3.0 (2006):
motorless adj 1: having no motor [syn: unmotorized, unmotorised, motorless] [ant: motored, motorised, motorized]