You can make glossaries for your courses.
Make a new library item and enter all words with their definitions in a new document. See How to Make a Library Item.
Click courses on the side bar.
Click edit on the course you want to add the glossary to.
Scroll down to Glossary and find the name of the glossary you want to go with that course.
The glossary will now be available to your students when they study your course in the top left corner of their screen and will look like this: