effort-n; 2 Senses

Sense Number 1: attempt

Commentary: endeavor, endeavour, try - earnest and conscientious activity intended to do or accomplish something (count noun)

He made an effort to cover all of the reading material for the class.
She gave a good effort.
The book was her finest effort.

PropBank: effort.01
WordNet 2.0 Sense Numbers: 1, 3, 4

Sense Number 2: exertion

Commentary: elbow grease, travail, sweat - use of physical or mental energy; hard work (mass noun)

He got an A for effort.
They managed only with great effort.

PropBank: NM
WordNet 2.0 Sense Numbers: 2