SECULARIZA'TION, noun. [foom secularize.] the act of converting a regular person, place or benefice into a secular one. Most cathedral churchses were formerly regular, that is, the canons were of religious or monastic orders; but they have since been secularized. for the secularization of a regular church, there is wanted the authority of the pope, that of the prince, the bishop of the place, the patron, and even the consent of the people.