1. secret cooperation or conspiracy, especially for an illegal or deceitful purpose

Examples

• The investigation revealed collusion between the two companies to fix prices.
• There was evidence of collusion among the bidders at the auction.
• The scandal involved collusion between government officials and contractors.
• They were accused of collusion to manipulate the election results.
• The court found no proof of collusion between the defendants.
• Corporate collusion can harm consumers by reducing competition.