[id.i.o.syn.cra.sy] n, pl -sies [Gk idiosynkrasia, fr. idio- + synkerannynai to blend, fr. syn- + kerannynai to mingle, mix--more at crater] (1604) 1 a: a peculiarity of constitution or temperament: an individualizing characteristic or quality b: individual hypersensitiveness (as to a drug or food)
2: characteristic peculiarity (as of temperament); broadly: eccentricity -- id.i.o.syn.crat.ic adj -- id.i.o.syn.crat.i.cal.ly adv