Unpardonable
The Century Dictionary and Cyclopedia
Not to be forgiven; incapable of being pardoned or remitted: as, an
unpardonable
insult.
the GNU version of the Collaborative International Dictionary of English
adjective.
Not admitting of pardon or forgiveness; inexcusable.
Wiktionary, Creative Commons Attribution/Share-Alike License
adjective.
impossible
to
pardon
; impossible to
excuse
or
justify
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
not admitting of pardon