(1) “Airport” means any area of land or water designed and set aside for the landing and taking off of aircraft and utilized or to be utilized in the interest of the public for such purposes;

(2) “Airport hazard” means any structure or tree or use of land that obstructs the airspace required for the flight of aircraft in landing or taking off at an airport or is otherwise hazardous to such landing or taking off of aircraft;

(3) “Airport hazard area” means any area of land or water upon which an airport hazard might be established if not prevented as provided in this chapter;

(4) “Incompatible use” means any structure or use of land, as identified in airport noise compatibility planning, in title 14 of the Code of Federal Regulations, part 150, which was promulgated pursuant to the former Aviation Safety and Noise Abatement Act of 1979, 49 U.S.C. § 2101 et seq. [repealed], concerning the exposure of residents or occupants in the vicinity of airports to aircraft noise; provided, that “incompatible use” does not apply in any county having a metropolitan form of government and having a population greater than one hundred thousand (100,000), according to the 1990 federal census or any subsequent federal census;

(5) “Person” means any individual, firm, copartnership, corporation, company, association, joint stock association, or body politic and includes any trustee, receiver, assignee, or other similar representative thereof;

(6) “Political subdivision” means any municipality or county;

(7) “Structure” means any object constructed or installed by humans, including, but not limited to, buildings, towers, smokestacks, and overhead transmission lines; and

(8) “Tree” means any object of natural growth.