What's the adjective for secularised? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs secularize and secularise which may be used as adjectives within certain contexts.
“They are the ritual gestures of religious dogmatists who have lost their unquestioned authority in pluralistic and secularistic cultures.”
“In the modern public square, one tends to find religion on one side, a secularistic outlook on the other, and the notion of the secular or secularity in between.”