The ruling planet of a nativity, which determines the length of life of the native. Also called apheta, hyleg. Contrasted with anareta.
Mid 17th century; earliest use found in William Lilly (1602–1681), astrologer. From post-classical Latin prorogator person who prolongs, person who dispenses or distributes, ruling planet of a nativity from classical Latin prōrogāt-, past participial stem of prōrogāre + -or.