Motor car \Motor car\, or Motorcar \Mo"tor*car`\, n. 1. An automobile, locomobile, or locomotive designed to run and be steered on a street or roadway; esp., an automobile specially designed for passengers and propelled by an internal combustion engine. Syn: car, auto, automobile, machine. [Webster 1913 Suppl.] 2. (Elec. Railroads) Any car containing motors for propulsion. [U. S.] [Webster 1913 Suppl.]