IPA: /ɪnˈdɛvaʊt/
KK: /ɪnˈdɛvaʊt/
Not showing strong religious beliefs or practices.
He was considered indevout because he rarely attended church services.
Indevout is formed from "in-" (meaning not) and "devout" (from Old French *devot*, meaning devoted or pious). The word means not devoted or lacking in piety.
Think of 'not' ('in-') being combined with 'devoted' — that's why indevout means lacking devotion.