'Motive power' definitions:

Definition of 'motive power'

From: WordNet
noun
The power or ability to move [syn: locomotion, motive power, motivity]

Definition of 'Motive power'

From: GCIDE
  • Motive \Mo"tive\, a. Causing motion; having power to move, or tending to move; as, a motive argument; motive power. "Motive faculty." --Bp. Wilkins. [1913 Webster]
  • Motive power (Mach.), a natural agent, as water, steam, wind, electricity, etc., used to impart motion to machinery; a motor; a mover. [1913 Webster]