12 letters · 21 points in Scrabble
noun a behavioral attribute that is distinctive and peculiar to an individual
originFirst attested in 1604, in modern sense since 1665, from Ancient Greek ἰδιοσυγκρασία (idiosunkrasía, “one’s own temperament”), from ἴδιος (ídios, “one’s own”) + σύν (sún, “together”) + κρᾶσις (krâsis, “temperament”). By surface analysis, idio- + syn- + -crasy.
Etymology from Wiktionary, CC BY-SA 3.0