id ‧ i ‧ o ‧ mat ‧ ic /ˌɪdiəˈmætɪk◂/ BrE AmE adjective
1 . idiomatic expression/phrase an idiom
2 . typical of the natural way in which someone speaks or writes when they are using their own language:
He had the ability to write fluent and idiomatic English.
the idiomatic richness of the Spanish language
—idiomatically /-kli/ adverb