IPA: /ˌɪrɪˈlɪdʒəs/
KK: /ɪrɪˈlɪdʒəs/
Not having or showing any religious beliefs or feelings; showing indifference or hostility towards religion.
His irreligious views often led to debates with his more devout friends.
Irreligious → It is formed from "in-" (meaning not) and "religio" (from Latin, meaning religion). The word "irreligious" means not having or showing a belief in religion.
Think of 'not' ('in-') having a belief in 'religion' ('religio') — that's why irreligious means lacking religious belief.