idiomaticallyadv.

1683 W. Walker Treat. Eng. Particles (ed. 8) cv. 431 After you put for thou, we do not set a Verb, or sign a Verb ending in st, not saying you lovedst or didst love, but You loved or did love, the Verb and sign ending in st, idiomatically coming after thou.

1761 Monthly Rev. Nov. 355 ‘The head became vertiginous,’ says Mr. Nourse's [translator], more idiomatically.

1828 T. De Quincey Elements Rhetoric in Blackwood's Edinb. Mag. Dec. 905/2 Men..wrote idiomatically, because they wrote naturally, and without affectation.

1864 T. Prendergast Mastery Lang. xii. 208 But to speak a language otherwise than idiomatically, is to speak it imperfectly.

1913 G. W. E. Russell Half-lengths vi. 177 He spoke English as fluently as I did, but not quite idiomatically; and there was just a trace of an accent which was not English.

1942 ‘M. Innes’ Daffodil Affair ii. v. 64 ‘He didn't die,’ said Hudspith. ‘He perished.’ ‘He did a perish,’ said Appleby corroboratively and idiomatically.

2006 N.Y. Times (National ed.) 5 Nov. v. 3/1 Kouyou, which can be translated literally as ‘red leaves’ or idiomatically as ‘changing colors’,..is as important to the Japanese as their fabled cherry blossom festival in the spring.