Many people, especially clients, are completely unaware of how much research can be required for what they might view as a “simple” translation.
The actual time that needs to be invested is dependent on many factors. The worst case scenario, of course, is when a translator is doing a highly technical piece that is not in their areas of specialization. This can be akin to starting from scratch, with the translator having to almost literally look up every word and research every concept. While this is, professionally speaking, not supposed to happen – a translator is always supposed to be working in fields with which they are conversant and have experience – it clearly does.
There are also situations where, even for a seasoned translator, an unusual amount of research might be required, due to either the subject or the particular language of the text. This can be especially true for academic papers, which by their very nature tend to be esoteric if not arcane in nature. A translator who may have successfully handled any number of, say, philosophy projects, could be confronted with a translation of an obscure text about a little known theory about which he is not even slightly conversant. This type of project would require not just searching for the definition of specific terms, but the actual reading of primary source material on the particular subject.
As for basic word definitions, the first stop is still dictionaries, whether paper or virtual. Many translators, dependent on the field, work with specialized dictionaries, of which there are thousands. From legal to medical, technical to culinary, and running the gamut of literally thousands of sub-specialties.
If that fails, the next step for most translators is doing a Google search in an attempt to locate the particular word or phrase. The purpose of this is that, by reading the text in the source language, one will be able to deduce the meaning from the context.
There are also a number of translation websites that allow one to post questions related to vocabulary or phrases. While some can be quite helpful, others tend to be more hit or miss.
There are times, however, when a translator has to go even further. In some cases, as noted above, one can research within the field itself, learning more, understanding more and, hopefully, being able to make a correct linguistic leap. Professionals in the field in question can also be contacted. This can often be quite successful, given that most people, if they have the time, are often delighted to discuss their own area of interest.
A translator should never hesitate to invest in research tools, such as specialty dictionaries, in any field in which they are working. Some new to the profession might be leery of this sort of investment, but it will literally pay for itself in a very short term, both in terms of your time and your professional development.