There can be only one glossary in a scene and it can be found in the lower section within the scene. Only those terms are available within a scene, that the owner of the scene gave members access to. 

You can open the glossary in full size with the buttom at the right side of the screen. 





If the professor gives them permission, then members can also edit the glossary. In this case you can import your personal glossary (or a part of it) into the scene's glossary with the button of "Select sources". Here you can select which folders you would like to import to the scene's Glossary. 

There is also a search field in the Glossary, where you can easily search for a certain term or definition.