The Collaborative International Dictionary of English v.0.48:

Propel \Pro*pel"\, v. t. [imp. & p. p. Propelled; p. pr. & vb.
   n. Propelling.] [L. propellere, propulsum; pro forward +
   pellere to drive. See Pulse a beating.]
   To drive forward; to urge or press onward by force; to move,
   or cause to move; as, the wind or steam propels ships; balls
   are propelled by gunpowder.
   [1913 Webster]