efficient
efficient (ef*fish"ent) , adjective
[Latin efficiens, -entis, present participle of efficere to effect: compare French efficient. See Effect, n.]
Causing effects; producing results; that makes the effect to be what it is; actively operative; not inactive, slack, or incapable; characterized by energetic and useful activity; as, an efficient officer, power.
The efficient cause is the working cause.
Efficient , noun
An efficient cause; a prime mover.
God... moveth mere natural agents as an efficient only.