What is the meaning of effort?

noun

• Earnest and conscientious activity intended to do or accomplish something.
  • usage: "made an effort to cover all the reading material"; "wished him luck in his endeavor"; "she gave it a good try"
  • synonyms: attempt, endeavor, endeavour, try
• Use of physical or mental energy; hard work.
  • usage: "he got an A for effort"; "they managed only with great exertion"
  • synonyms: elbow grease, exertion, travail, sweat
• A notable achievement.
  • usage: "he performed a great feat"; "the book was her finest effort"
  • synonyms: feat, exploit
• A series of actions advancing a principle or tending toward a particular end.
  • usage: "he supported populist campaigns"; "they worked in the cause of world peace"; "the team was ready for a drive toward the pennant"; "the movement to end slavery"; "contributed to the war effort"
  • synonyms: campaign, cause, crusade, drive, movement