Pronunciation: (id"ē-u-sing'kru-sē, -sin'-), [key]
1. a characteristic, habit, mannerism, or the like, that is peculiar to an individual.
2. the physical constitution peculiar to an individual.
3. a peculiarity of the physical or the mental constitution, esp. susceptibility toward drugs, food, etc. Cf. allergy (def. 1). Also,idiocrasy.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.