The Collaborative International Dictionary of English v.0.48:
Collusive \Col*lu"sive\, a. 1. Characterized by collusion; done or planned in collusion. "Collusive and sophistical arguings." --J. Trapp. "Collusive divorces." --Strype. [1913 Webster] 2. Acting in collusion. "Collusive parties." --Burke. -- Col*lu"sive*ly, adv. -- Col*lu"sive*ness, n. [1913 Webster]