Specialized dictionaries & glossaries on the web
We are likely to find on the web dictionaries and glossaries about even the most specific topic. For example, typing "french wine dictionary" or "french wine dictionary grand cru" in Google will reveal several glossaries of wine-related terms.
We need however to pay special attention to the quality of web resources. Institutions such as the EU, governmental agencies, or universities can usually be trusted in their areas of competency: for administrative terms, diplomas equivalence, legal terms, etc.
For other sources, it is always necessary to check whether the term found is used in the expected context in the target language. Again a web search will do. If the search returns very few relevant documents containing the proposed term, this term is probably not correct. Incidently, this is how Google detects spelling mistakes.
You can also search past translations.