idiosyncraticEnglishOxford New American Dictionaryidiosyncratic /ˌidēəsiNGˈkradik, ˌɪdiəsɪŋˈkrædɪk / ▸ adjective relating to idiosyncrasy; peculiar or individual: she emerged as one of the great, idiosyncratic talents of the nineties. – DERIVATIVES idiosyncratically /ˌidēəsiNGˈkradək(ə)lē, ˌɪdiəsɪŋˈkrædək(ə)li / adverb– ORIGIN late 18th century : from idiosyncrasy, on the pattern of Greek sunkratikos ‘mixed together’.