non-collusion

noun

1. a secret agreement, especially for fraudulent or treacherous purposes; conspiracy: Some of his employees were acting in collusion to rob him.
2. Law. a secret understanding between two or more persons to gain something illegally, to defraud another of his or her rights, or to appear as adversaries though in agreement: collusion of husband and wife to obtain a divorce.

noun

1. secret agreement for a fraudulent purpose; connivance; conspiracy
2. a secret agreement between opponents at law in order to obtain a judicial decision for some wrongful or improper purpose

n.late 14c., from Old French collusion, from Latin collusionem (nominative collusio) “act of colluding,” from colludere, from com- “together” (see com-) + ludere “to play,” from ludus “game” (see ludicrous). “The notion of fraud or underhandedness is essential to collusion” [Fowler].