collusion

n. conspiracy; agreement formed with the intent to defraud (Law)

Collusion is a term to refer to acts of cooperation or collaboration among rival entities.
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Noun
1. secret agreement
(hypernym) agreement, arrangement
(derivation) conspire, collude
2. agreement on a secret plot
(synonym) connivance
(hypernym) agreement
(hyponym) cahoots
(derivation) conspire, collude

n. collusion, conspiracy; agreement formed with the intent to defraud (Law)

(n.)
An agreement between two or more persons to defraud a person of his rights, by the forms of law, or to obtain an object forbidden by law.
  

(n.)
A secret agreement and cooperation for a fraudulent or deceitful purpose; a playing into each other's hands; deceit; fraud; cunning.