11 letters · 14 points in Scrabble
adjective not capable of being improved on
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 surpassed English unsurpassed From un- + surpassed.
Etymology from Wiktionary, CC BY-SA 3.0