Futility (noun)

1. The state or quality of being futile; ineffectiveness or uselessness.
2. The state or quality of being futile; ineffectiveness or uselessness.

Origin:

From the latin word "futilis" meaning "worthless".

Examples:

1. The futility of her efforts to save the plant were apparent to everyone.
2. The futility of trying to reason with him became clear after the third attempt.
3. Despite the futility of the situation, he refused to give up.
4. The futility of war was evident in the destruction left in its wake.
5. She finally realized the futility of her actions and decided to move on.