For the purposes of this article, the following terms shall be deemed to have the meanings respectively ascribed to them in this section:
(1) MUNICIPALITY. A municipal corporation in the State of Alabama.
(2) PUBLIC GAS CORPORATION. A public corporation having corporate power to own and operate one or more gas systems and existing under the provisions of any of the following: Articles 8, 9, and 12 of this chapter.
(3) AUTHORIZING MUNICIPALITY. Each municipality which authorized the incorporation of a particular public gas corporation or the governing body of which consented to, or made determinations prerequisite to, the incorporation of a particular public gas corporation.
(4) GAS SYSTEM. A plant and system for the manufacture and distribution of gas or a system for the purchase, transportation, and distribution, or any of them, of manufactured or natural gas, together with all appurtenances thereto and all property used or useful in connection therewith, including franchises.
(5) COMMISSION. Alabama Public Service Commission.
(6) REGULATED UTILITY. A corporation that is a utility within the meaning of Section 37-4-1 and that is subject to regulation by the commission.
Each of the foregoing definitions shall be deemed applicable whether the word defined is herein used in the singular or plural.