I'm not sure if this helps, but there are several multilingual terminology websites in existence, so if you know the term in one language, you'll likely be able to look it up in another.
, a multilingual terminology database that, as I understand, was once updated by INTERPOL. I don't think that it's updated anymore, though.Termium
, the terminology database used by the government of Canada. It has quite a collection of terms in English, French and Spanish, and apparently they have Portuguese now, too.termwiki.com
. A wiki-like environment to search for terms in several languages. You can search by subject, but you don't get a diagram, like what you said you wanted earlier.
The above sites work well if you know what you're looking for in one language, but not if you're working in just one language and want to know what a specific part of a specific thing.
You could try doing a Google image search of "<general thing>
diagram." In many cases, you may just find exactly what you're looking for.