When a glossary is created, if "No" is selected in the "Allow comments on entries" option, it's still possible to do comments to the terms already posted.
Follow these steps to replicate the bug:
1 - Create a "Glossary".
2 - Select "No" in the "Allow comments on entries" option.
3 - Log In as a student
4 - Add comments to the glossary.
Bug: The glossary allows students to comment the entries.