12 letters · 17 points in Scrabble
adjective not responding to some influence or stimulus
adjective aloof or indifferent
adjective not susceptible to suggestion or influence
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 responsive English unresponsive From un- + responsive.
Etymology from Wiktionary, CC BY-SA 3.0