Id·i·o·syn·cra·sy (ĭd′ē-ō-sĭng′krə-sē) n. pl. id·i·o·syn·cra·sies 1. A structural or behavioral characteristic peculiar to an individual or group. 2. A physiological or temperamental peculiarity. 3. An unusual individual reaction to food or a drug.
[Greek idiosunkrāsiā : idio-, idio- + sunkrāsis, mixture, temperament (sun-, syn- + krāsis, a mixing; see kerə- in Indo-European roots).]
