Inexpiable, a.
Etymology: [L. inexpiabilis: cf. F. inexpiable. See In- not, and Expiable.]
1. Admitting of no expiation, atonement, or satisfaction; as, an inexpiable crime or offense. Pomfret.
2. Incapable of being mollified or appeased; relentless; implacable. [Archaic] "Inexpiable hate." Milton. They are at inexpiable war with all establishments. Burke.
Shades of meaning
Fernald lists inexpiable only as an antonym, under venial.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given