Efficient

1. (a.) Productive; adept; characterized by energetic and useful activity; as, an efficient officer, power.

2. (n.) An efficient cause; a prime mover.

Thesaurus Entries

able, active, adequate, au fait, banausic, capable, competent, economic, effective, effectual, efficacious, equal to, feasible, fit, fitted, fitted for, functional, go, journeyman, operable, operational, operative, practicable, practical, pragmatic, productive, proficient, qualified, realizable, suited, thrifty, unwasteful, up to, up to snuff, well-fitted, well-qualified, well-suited, workable, worthy