What is Affidavit Of Merits?

Legal Definition
One setting forth that the defendant has a meritorious defense (substantial and not technical) and stating the facts constituting the same. Palmer v. Rogers, 70 Iowa, 381, 30 N. W. 645,
-- Black's Law Dictionary
Legal Definition
An affidavit stating that the defendant has stated his case and all of the facts of his case to his attorney and is by him informed and verily believes that he has a good defense to the merits of the action. See 20 Pa. 387, 59 Am. Dec. 728.
-- Ballentine's Law Dictionary