Hi Steve,
The Glossary activity in Moodle is more than a list of entries and definitions. It offers the powerful feature to automatically generate autolinks to the entries in many of the various resources and activities on a moodle course.
If you need to retain the autolink feature, then you would need to enter your "dictionary" into a glossary. But... buidling a glossary or dictionary is a tough task, it is really a job for professional lexicographers. On top of that you want your glossary to be multilingual, which will stretch things even further.
If, on the other hand, you do not need the autolink feature and all you want is to provide your students with an online multilingual dictionary, the simplest solution is to provide in your courses a link (or links) to one or more online dictionaries - there are plenty available, in all the languages you need.
Joseph