idiomatic

Auld lang syne” is Scottish-Gaelic for “old long since,” or, more idiomatically, “days gone by” or “time long past.

It follows that we cannot conclude anything as to the origin of a tale from the fact that it is told idiomatically.

The Guicowar speaks English well, not only correctly and fluently, but idiomatically.

He laughed with pleasure and surprise at finding that he could still speak his native tongue quite fluently and idiomatically. '