1. being effective without wasting time or effort or expense

- an efficient production manager

- efficient engines save gas

Similar word(s): competent, effective, effectual, efficacious, businesslike, economic, economical, expeditious, streamlined

2. able to accomplish a purpose; functioning effectively

- an efficient secretary

- the efficient cause of the revolution

Similar word(s): competent, effective

Sentences with efficient as an adjective:

- An efficient process would automate all the routine work.

- Our cleaners are almost too efficient: they throw away anything left out on a desk.

- The motor is only 20% efficient at that temperature.

- Ownership, maintenance, or use of the automobile need not be the direct and efficient cause of the injury sustained