Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

propelling
     adj : tending to or capable of propelling; "propellant fuel for
           submarines"; "the faster a jet plane goes the greater
           its propulsive efficiency"; "universities...the seats
           of propulsive thought" [syn: {propellant}, {propellent},
            {propulsive}]

propel
     v 1: cause to move forward with force; "Steam propels this ship"
          [syn: {impel}]
     2: give an incentive for action; "This moved me to sacrifice my
        career" [syn: {motivate}, {actuate}, {move}, {prompt}, {incite}]
     [also: {propelling}, {propelled}]

propelling
     See {propel}