what is the definition of idiosyncrasies
idÂ·iÂ·oÂ·synÂ·craÂ·sy. n. pl. idÂ·iÂ·oÂ·synÂ·craÂ·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.dâ¢iâ¢oâ¢synâ¢craâ¢sy. 1. a characteristic, habit, mannerism, etc., that is peculiar to or distinctive of an individual. 2. the physical or mental constitution peculiar to an individual. 3. a peculiarity of the physical or mental constitution, esp. a sensitivity to drugs, food, etc.