Collusion means a secret agreement for deceitful or illegal purpose .
Collusion comes under noun.
Synonyms: collaboration, secret, agreement, intrigue, conspiracy, fraud, complicity.
Recently there were some claims made by the people that there was a collusion in the death of our Chief Minister YSR.
It was clear that the local service stations were in collusion; their petrol prices were identical and always changed on the same day.