(a) “Person” means any individual, firm, copartnership, joint venture, association, corporation, estate, trust, or any other group or combination acting as a unit, and the plural as well as the singular number unless the intention to give a more limited meaning is disclosed by the context.

(b) “Highway” means and includes every way or place, of whatever nature, including public roads, toll roads, streets, and alleys of the state generally open to the use of the public or to be opened or reopened to the use of the public for the purpose of vehicular travel, and notwithstanding that they may be temporarily closed for the purpose of construction, reconstruction, maintenance or repair. Provided further, that the confines of a highway shall include the entire width and length of the right-of-way.

(c) “Motor vehicle” means every vehicle licensed for highway use by which any person or property is transported or drawn upon the highways of this state and which is self-propelled.

(d) “Liquefied compressed gas” means gases derived from petroleum or natural gas which are in the gaseous state at normal atmospheric temperature and pressure, but which may be maintained in the liquid state at normal atmospheric temperature by suitable pressure. The term shall be deemed to mean and include methane, ethane, propane, ethylene, propylene, butylene, butane, isobutane, and any and all liquid flammable materials derived from petroleum or natural gas having a vapor pressure exceeding forty (40) pounds per square inch, absolute, at one hundred (100) degrees F. Normal storage of these gases is a liquid under pressure.

(e) “Compressed natural gas” and “liquefied natural gas” mean natural gas after it has been compressed or liquefied for use as a fuel in a motor vehicle and shall not include natural gas prior to such final compression or liquefication.

(f) “Compressed gas” means “liquefied compressed gas,” “liquefied natural gas,” “compressed natural gas” and any other liquefied or compressed gas that is used or is usable as fuel in a motor vehicle.

(g) “Use” means, in addition to its original meaning, the receipt of compressed gas by any person into the fuel supply tank of a motor vehicle or into a receptacle from which compressed gas is supplied by any person to his own or other motor vehicles.

(h) “Terminal” means a tank farm within this state with the minimum storage capacity for the receipt of a full barge delivery or common carrier pipeline delivery of compressed gas.

(i) “Refiner” or “processor” means every person who shall produce, manufacture, refine, distill, compress or liquefy compressed gas in this state.

(j) “Public utility” means a person engaged in the distribution of natural gas whose rates are subject to regulation by the Public Service Commission of the State of Mississippi.

(k) “Distributor” means any person who sells or delivers compressed gas for use in the operation of a motor vehicle or motor vehicles on the highways of this state and any person who shall import, receive, purchase, acquire, manufacture, refine, use, store or sell any compressed gas in this state, on which the excise taxes hereinafter levied by this chapter have not been paid or the payment of which is not covered by the bond of a qualified Mississippi distributor of compressed gas. All “refiners” and “processors” shall qualify as distributors of compressed gas. All persons operating marine or pipeline terminals and all persons operating underground storage facilities exclusive of those storing natural gas shall qualify as distributors of compressed gas. No person may qualify as a distributor for the sole purpose of using compressed gas as a fuel to propel a motor vehicle or motor vehicles owned by him on the highways of this state.

(l) “User” means any person who uses compressed gas to propel a motor vehicle over the highways of this state.

(m) “Commission” or “department” means the Department of Revenue of the State of Mississippi, either acting directly or through its duly authorized officers, agents and employees.

(n) “United States government” means and includes all purchasing officers of the Armed Forces of the United States and the United States Property and Fiscal Officer for the State of Mississippi or any other state, appointed pursuant to Section 708, Title 32, United States Code, when purchasing compressed gas with federal funds for the account of and use by a component of the Armed Forces as defined herein.

(o) “Armed Forces” means and includes all components of the Armed Forces of the United States, including the Army National Guard, the Army National Guard of the United States, the Air National Guard and the Air National Guard of the United States, as those terms are defined in Section 101, Title 10, United States Code, and any other reserve component of the Armed Forces of the United States enumerated in Section 261, Title 10, United States Code.

(p) “Diesel gallon equivalent” means six and six one-hundredths (6.06) pounds of liquefied natural gas. Provided, however, that should the National Conference on Weights and Measures subsequent to July 1, 2015, adopt a diesel gallon equivalent definition different than six and six one-hundredths (6.06) pounds of liquefied natural gas, the term “diesel gallon equivalent” shall mean and have the same definition as the National Conference on Weights and Measures definition.