Wiktionary
adv. In an unpardonable manner.
WordNet
adv. in an unpardonable manner or to an unpardonable degree; "he was inexcusably cruel to his wife" [syn: inexcusably, unforgivably] [ant: excusably, excusably, excusably]
Usage examples of "unpardonably".
My conduct was as unpardonably criminal in this, as it was in greater things.
I am writing a letter to Darya Pavlovna, whom I have so unpardonably forgotten until now.
I think some of us wounded her deeply and unpardonably by continuing to associate her with Sibley, after he revealed what an unmitigated rascal he was.
The Democrats had unpardonably connived with one of the greatest evils of the twentieth century.
But they who most unpardonably calumniate this Christian era, are the very men who either themselves fled for asylum to the places specially dedicated to Christ, or were led there by the barbarians that they might be safe.