IPA: /ˌɪdɪəˈmætɪkli/
KK: /ɪdɪəˈmætɪkli/
In a way that is natural and typical for a particular language or group of people, often using expressions that are not literally true.
She speaks idiomatically, using phrases that are common in her culture.
Idiomatically → It is formed from "idiom" (from Greek "idiōma", meaning a peculiar phrase or expression) and "-atically" (a suffix forming adverbs, meaning in a manner relating to). The word "idiomatically" means in a manner that relates to or uses idioms, or expressions that have a figurative meaning different from their literal meaning.
Think of the word 'idiom' which refers to a unique expression, and remember that 'idiomatically' means using expressions in that unique way.