11 letters · 19 points in Scrabble
adjective unwilling or unable to forgive or show mercy
adjective not to be placated or appeased or moved by entreaty
originEtymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Germanic *un- Proto-West Germanic *un- Old English un- Middle English un- English un- English forgiving English unforgiving From un- + forgiving.
Etymology from Wiktionary, CC BY-SA 3.0