Affidavit of no collusion

What does Affidavit of no collusion mean in American Law?

The definition of Affidavit of no collusion in the law of the United States, as defined by the lexicographer Arthur Leff in his legal dictionary is:

A kind of affidavit of good faith native to interpleader actions, in which the plaintiff states that the bill is not being filed in collusion with either of the defendants. In modern practice, it will usually be sufficient just to allege “no collusion” in the bill of interpleader itself (though in some jurisdictions the bill itself may require verification, i.e., some species of oath).