I don't know the solution, but the docs say this:
Restoring a glossary activity backup
An alternative method of importing glossary entries is to restore a glossary activity backup containing enrolled users. This method includes categories, images and attachments within glossary entries. When the glossary is restored, the authors of the entries will be the same as in the original glossary.
But in the meantime, it is rather simple to export the glossary entries in the first course and them import them in the next course. See attached,