The following terms, when used in this section and §§ 1.1081-2 to 1.1083-1, inclusive, shall have the meanings assigned to them in section 1083: Order of the Securities and Exchange Commission; registered holding company; holding company system; associate company; majority-owned subsidiary company; system group; nonexempt property; and stock or securities. Any other term used in this section and §§ 1.1081-2 to 1.1083-1, inclusive, which is defined in the Internal Revenue Code of 1954, shall be given the respective definition contained in such Code.