IPA: /ɪnˈɛkspɪəblɪ/
KK: /ɪnˈɛkspɪəblɪ/
In a way that cannot be atoned for or forgiven; in a manner that is irreparable or unredeemable.
His actions were inexpiably wrong, leaving no chance for forgiveness.
Inexpiably → It is formed from "in-" (meaning not) and "expiabilis" (from Latin, meaning able to be atoned for). The word "inexpiably" means in a manner that cannot be atoned for or made amends.
Think of 'not' ('in-') being able to be 'atoned for' ('expiabilis') — that's why inexpiably means something that cannot be made right.