13 letters · 24 points in Scrabble
adjective beyond doubt or reproach
adjective free of guilt; not subject to blame
adjective completely acceptable; not open to exception or reproach
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 impeachable English unimpeachable From un- + impeachable.
Etymology from Wiktionary, CC BY-SA 3.0