[经] 动力

[ noun ]
the power or ability to move
<noun.attribute>

Motive \Mo"tive\, a.
Causing motion; having power to move, or tending to move; as,
a motive argument; motive power. ``Motive faculty.'' --Bp.
Wilkins.

{Motive power} (Mach.), a natural agent, as water, steam,
wind, electricity, etc., used to impart motion to
machinery; a motor; a mover.