Lewis Short
collūdĭum | conl- (noun N) : (), , colludo (post-class.).
* A sporting, playing together: delphinorum,Sol. 12; so Symm. Ep. 3, 5.
* A secret, deceptive understanding, collusion, esp. in justice, Amm. 18, 5, 1; Cod. Th. 9, 42, 20; 11, 42, 7; Symm. Ep. 4, 20.
Charlton T. Lewis, Charles Short, A Latin Dictionary