11 letters · 16 points in Scrabble
adjective unthinking; prompted by (or as if by) instinct
originEtymology tree English instinct Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus Old French -ifbor. Middle English -yf English -ive English instinctive From instinct + -ive.
Etymology from Wiktionary, CC BY-SA 3.0