An affidavit is the written equivalent of verballygiven court testimony. A written statement that someone makes after promising officially to tell the truth.An affidavit can be used as proof in a law court. The disciplinary policy at Commerce allows only one punishment for "violation of 'no-strike' affidavit": removal. An Applicant Affidavit is a legal form used to provide additional information regarding crimes, negative actions, and applicant selfdisclosures. An affidavit is a written statement made under oath that is typically used in legal proceedings. Learn their purpose, when to use, and how to write. 'Affidavit' in a sentence: We have a signed affidavit stating that the two men were seen entering the building.