Affidavit: a sworn or affirmed statement made in writing and signed; if sworn, it is notarized. A written letter or statement that is signed before a notary public, in the form of a sworn statement.An affidavit of marriage is a legal document and a sworn statement submitted to the court or another institution, to verify that two people are married. You can apply for a marriage license from your county probate court. You must be at least 18 years old, of sound mind, and have no living spouse. An affidavit is a sworn statement signed under oath. Learn how affidavits can be used in your case in this mini guide. This guide is intended to provide researchers with information on the various types of marriage records found in Georgia. An affidavit of marriage is a legally binding document that proves a legal marriage exists between two people.