Employer
(2) Employer includes any person acting directly or indirectly in the interest of an employer in relation to an employee but shall not include the United States or any State or political subdivision of a State (except with respect to employees of a State or a political subdivision thereof, employed: (i) In a hospital, institution, or school referred to in the last sentence of section (r) of the Act, or (ii) In the operation of a railway or carrier referred to in such sentence), or any labor organization (other than when acting as an employer), or anyone acting in the capacity of officer or agent of such labor organization. (iii) Employ includes to suffer or permit to work.