As used in this part: “Municipality” and “legislative body” shall each have the same meaning ascribed to it in section 7-425; “participating municipality” means any municipality which votes to accept the provisions of this part; “fund” means the Policemen and Firemen Survivors’ Benefit Fund established by this part; “Retirement Commission” means the State Retirement Commission created by chapter 66; “member” means any active uniformed policeman or active uniformed fireman receiving pay from a participating municipality who has been included by such municipality under the provisions of this part, and “compensation” means one-twelfth of the annual rate of pay of a full-time paid policeman or fireman of a participating municipality who is in active service and one-twelfth of the annual rate of pay immediately prior to the retirement of a full-time paid policeman or fireman of a participating municipality who is retired.