Definition of idiosyncrasy :
A peculiarity of physical or mental constitution or temperament; a characteristic belonging to, and distinguishing, an individual; characteristic susceptibility; idiocrasy; eccentricity.
specialty (part of speech: noun)
forte, cachet, individuality, quirk, quality, property, discriminant, particularity, specialization, definiteness, characteristic, hallmark, stamp, flavor, trait, mannerism, specialty, way, feature, figure, keynote, mark
unconformity (part of speech: noun)
curiosity, impropriety, funniness, incongruity, exception, quirkiness, divergence, inconsistency, incompatibility, oddity, strangeness, difference, unfamiliarity, peculiarity, aberrance, nonconformity, derangement, uniqueness, outlandishness, deviation, anomaly, aberration, singularity, uncommonness, irregularity, unconventionality, eccentricity, abnormality, freakishness
- This idiosyncrasy of Gen. - "The Struggle for Missouri", John McElroy.
- I have no fable at hand to explain what seems the special preference of the birds for this garden; it is possibly an idiosyncrasy, something like that of the cats which make Trajan's Forum their favorite resort. - "Roman Holidays and Others", W. D. Howells.
- Age, idiosyncrasy, tolerance, and disease, all exert modifying influences on the action of a poison. - "Aids to Forensic Medicine and Toxicology", W. G. Aitchison Robertson.