Willpower (noun)

1. The ability to control one's thoughts and actions in order to achieve a goal or overcome an obstacle.
2. The determination to do something despite difficulty or opposition.
3. The strength of one's willpower is the ability to resist temptations or overcome obstacles.

Origin:

The word "willpower" comes from the combination of the words "will" and "power", it refers to the mental or emotional strength that allows one to control one"s thoughts and actions in order to achieve a goal or overcome an obstacle.

Examples:

1. It took a lot of willpower to quit smoking.
2. She had the willpower to stick to her diet and lose weight.
3. He had to dig deep and use his willpower to finish the race.
4. It requires a great deal of willpower to resist the temptation to give up.
5. The willpower to achieve success is often the deciding factor.