noun
target language; language being translated to
Technical term used in translation contexts to refer to the language into which a text is being translated.
翻訳先言語が英語の場合、自然な表現を心がけてください。
When the target language is English, please aim for natural expressions.
原言語 is the language of origin from which a translation is made, while 翻訳先言語 is the target language into which it is translated.
Compound of 翻訳 (translation) + 先 (destination) + 言語 (language).