12 letters · 20 points in Scrabble
adjective not convincing
adjective having a probability too low to inspire belief
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 convincing English unconvincing From un- + convincing.
Etymology from Wiktionary, CC BY-SA 3.0