“Subdivision” means the division, by any subdivider, of any unit or units of improved or unimproved land, or any portion thereof, shown on the latest equalized county assessment roll as a unit or as contiguous units, for the purpose of sale, lease or financing, whether immediate or future except for leases of agricultural land for agricultural purposes. Property shall be considered as contiguous units, even if it is separated by roads, streets, utility easement or railroad rights-of-way. As used in this section, “agricultural purposes” means the cultivation of food or fiber or the grazing or pasturing of livestock. (Ord. 441 § 1 (part), 1988)