The question is relevant mainly for text-based studies. Unless you want to predetermine what you will recognize as translation (and therefore include in a research project, for instance), it seems wise to assume that the term ‘translation’ that you encounter in your primary texts does not have a fixed meaning. You can then explore the specific meaning, or range of meanings, it appears to have in the documents you are looking at.
There are complicating factors, though.
Firstly, try as you might to keep an open mind, you cannot entirely shake off the idea of translation that you take for granted. As a result, you will probably not be prepared to accept just anything as translation. In other words, the observer’s preconceptions undoubtedly play a part.
Secondly, you may be working with texts in foreign languages, perhaps texts from a remote past. How will we know when to qualify ‘xyz’ as ‘translation’? Describing ‘xyz’ as English ‘translation’ requires that we translate it. But when we translate it, we actually make it conform to English ‘translation’, and we do do on the terms of English ‘translation’.
Thirdly, it may be worth wondering how clear we are about how far ‘translation’ extends in English – or indeed how far corresponding (?!) terms in other languages extend. Perhaps we are not so sure after all about what ‘translation’ means in our native tongue.
A question, therefore, without a straight answer.