The existing use (residential, commercial, agricultural, light industrial, etc.) of a parcel of real property which is zoned for a more limited or other use in the city or county’s general plan. usually such use is permitted only if the property was being so used before the adoption of the zoning ordinance which it violates. example: a corner parcel has been used for a gasoline station for years, and now the city has zoned the entire area as residential (for homes only). the non-conforming use will be allowed as “grandfathered in,” but if the station is torn down the only use would be residential.