“Nonconforming use” means a lawful use of land or structure existing at the time of the passage of the ordinance from which these provisions derive, or any amendment thereto, which use or structure does not conform with the requirements of this title or its amendments. (Ord. 1998-11 § 4: Ord. 1985-6 § 4 (part); prior code § 5-2-2(SS))