意译（literal translation）,音译(transliteration)的英文科学定义!还有“直译”英语怎么说?

音译(transliteration)
Transliteration is a mapping from one system of writing into another.Transliteration attempts to be lossless,so that an informed reader should be able to reconstruct the original spelling of unknown transliterated words.To achieve this objective transliteration may define complex conventions for dealing with letters in a source script which do not correspond with letters in a goal script.Romaji is an example of a transliterating method.
This is opposed to transcription,which maps the sounds of one language to the script of another language.Still,most transliterations map the letters of the source script to letters pronounced similarly in the goal script,for some specific pair of source and goal language.
One instance of transliteration is the use of an English computer keyboard to type in a language that uses a different alphabet,such as in Russian.While the first usage of the word implies seeking the best way to render foreign words into a particular language,the typing transliteration is a purely pragmatic process of inputting text in a particular language.Transliteration from English letters is particularly important for users who are only familiar with the English keyboard layout,and hence could not type quickly in a different alphabet even if their software would actually support a keyboard layout for another language.Some programs,such as the Russian language word processor Hieroglyph provide typing by transliteration as an important feature.The rest of the article concerns itself with the first meaning of the word,that is rendering foreign words into a different alphabet.
If the relations between letters and sounds are similar in both languages,a transliteration may be (almost) the same as a transcription.In practice,there are also some mixed transliteration/transcription systems,that transliterate a part of the original script and transcribe the rest.Greeklish is an example of such a mixture.
In a broader sense,the word transliteration is used to include both transliteration in the narrow sense and transcription.Anglicizing is a transcription method.Romanization encompasses several transliteration and transcription methods.
意译（literal translation）
"Translation" is,etymologically,a "carrying across" or "bringing across":the Latin translatio derives from transferre (trans,"across" + ferre,"to carry" or "to bring").The modern European languages,Romance,Germanic and Slavic,have generally formed their own equivalent terms for this concept after the Latin model:after transferre or after the kindred traducere ("to lead across" or "to bring across").Additionally,the Greek term for "translation," metaphrasis (a "speaking across"),has supplied English with "metaphrase," meaning a literal,or word-for-word,translation,as contrasted with "paraphrase" (a "saying in other words," from the Greek paraphrasis).
直译：a word-for-word translation,其实literal translation也代表直译