Pronunciation: (ef'urt),[key] —n. 1. exertion of physical or mental power: It will take great effort to achieve victory. 2. an earnest or strenuous attempt: an effort to keep to the schedule. 3. something done by exertion or hard work: I thought it would be easy, but it was an effort. 4. an achievement, as in literature or art: The painting is one of his finest efforts. 5. the amount of exertion expended for a specified purpose: the war effort. 6. Chiefly Brit. a. an organized community drive or achievement.
b. a fund-raising drive.
7. Mech.the force or energy that is applied to a machine for the accomplishment of useful work.