n. 1. The use of physical or mental energy to do something; exertion. 2. A difficult exertion of strength or will: It was an effort to get up. 3. A usually earnest attempt: Make an effort to arrive promptly. 4. Something done or produced through exertion; an achievement: a play that was his finest effort. 5. Physics a. Force applied against inertia. b. The force needed by a machine to accomplish work on a load. [Middle English, from Old French esfort, from esforcier, to force, exert, from Medieval Latin exfortiāre : Latin ex-, ex- + Latin fortis, strong; see bhergh-2 in the Appendix of Indo-European roots.] effort·ful adj. effort·ful·ly adv. |
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