faithful translation
A faithful translation is one which conveys the message as the author intended it. For example, a literal word-for-word translation of 'it was raining cats and dogs' would be nonsensical and would not faithfully convey the original as the author intended it. The translator would have to find an equivalent idiom in the target language in order to convey the meaning of the original.
I acknowledge that this level of excellence requires:
- mastery of the target language equivalent to that of an educated native speaker;
- up-to-date knowledge of the subject material and its terminology in both languages;
- access to information resources and reference materials, and knowledge of the tools of my profession;
- continuing efforts to improve, broaden, and deepen my skills and knowledge.

- source: ATA (http://www.atanet.org//certification/online_ethics_code.php)