Curveball (noun)

1. A type of pitch in baseball thrown with a curved trajectory.
2. A pitch in baseball that is thrown with a curved trajectory, making it difficult for the batter to hit.
3. A tactic or strategy that is unexpected and throws off an opponent or adversary.

Origin:

19th century: from the verb curve + ball.

Examples:

1. The pitcher threw a curveball and the batter struck out.
2. The curveball was the pitcher's best pitch.
3. The curveball caught the batter off guard.
4. The lawyer's curveball argument caught the opposing counsel off guard.
5. The curveball was a winning strategy in the game.