At the beginning of all, could we find every word that we need to check up in the dictionaries at hand? I’m afraid the answer is no unless you just have to deal with articles written long ago. When something just appears in English, it’s quite likely that even people in that filed have not yet found a correspondent term for it. Then, most of the time, some papers or magazines would choose a term for it. However, as we all know that the dictionaries are hard to catch up with the fashion- they need to be authoritative rather than be state of the art. So when we have to do some translation work, we may have to find some certain terms on line or by asking people who works in that field. Or you may even choose a term by yourself. As I know, the Chinese name for All Saints is suggested by a reader of a popular paper-then never changed! I think that reader would feel quite honored! (来源：老牌的英语学习网站 http://www.EnglishCN.com)

Second, would you have time to check up every dictionary you got to do your work? Unless you do it for fun, or the answer is definitely no. Some translators may translate 10000 words in a single day. Searching in dictionaries would take up much time. The best way is collect what you need in your own dictionary and import them into the CAT you use-if you have one. Then you could save much time and labor in later works.

Saying so much, I think clever you would have got the answers. -)