1. The use of physical or mental energy to do something; exertion.
2. A difficult exertion of the 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. Force applied against inertia.
1. imparting vitality and energy
2. supplying motive force
1. the activity of causing to have energy and be active