As used in sections 476.575, 476.580, 476.585, 476.590, and 476.595 of this act *, the following terms shall mean:
(1) "Board", the board of trustees of the Missouri state employees' retirement system;
(2) "Judge", a judge of the supreme court, judge of the court of ** appeals, circuit court, the St. Louis court of criminal corrections, court of common pleas, associate division of the circuit court, probate division of the circuit court, and commissioner of the supreme court, and all retired judges and commissioners of such courts.