Steve Wynn to Judge -- Shut Joe Francis Up ... FOR GOOD!

Casino mogul Steve Wynn wants to make damn sure Joe Francis never calls him a wannabe murderer ever again -- and is now asking a judge to put a big fat sock in Francis' mouth.

Wynn just filed a request for a permanent injunction against Francis, claiming the "Girls Gone Wild" honcho is likely to continue to make false and defamatory accusations if the court doesn't stop him.

Wynn says he's afraid Francis is a loose cannon if left unchecked -- and any accusations he makes against Wynn are likely to cause irreparable harm ... specifically accusations about Wynn trying to murder him.

You'll recall, Francis recently LOST after Wynn sued him for defamation. Wynn claimed Francis made bogus claims that Wynn threatened to have him murdered over a gambling debt.