Collusion (noun)

1. Secret or illegal cooperation or conspiracy, especially in order to cheat or deceive others.
2. Secret or illegal cooperation or conspiracy, especially in order to cheat or deceive others, or to gain an illegal or unethical advantage.

Origin:

From latin collusiō ("a playing together, a trick, fraud"), from colludere ("to play together, act in concert, conspire"), from com- ("together") + ludere ("to play").

Examples:

1. The investigation revealed that the companies were involved in collusion to fix prices.
2. The athletes were found guilty of collusion in fixing the game's outcome.
3. The collusion between the politicians and the business leaders was illegal.
4. The act of collusion is a criminal offense.
5. The collusion between the two companies was exposed in the court.