Go to the correct letter index page
Go to one of the letter index pages in the glossary; for example A, B, and so on. You can jump to a letter index page from the alpha navigation bar at the top of every glossary page.
It is important to start from the right letter index page to have the new definition page appear in the right location in the hierarchy, as a child of the letter index page. Although the definition page can be moved later, it is easiest to create it in the right location to begin with.
Check your permissions
If you are able to create and edit pages in the glossary you will see a green "Tips for authors" section at the top of the letter index page. It will direct you to use the "Add a new item" link at the bottom of the letter index page to add a new term to the glossary.
Use the "Add a new term to the glossary" form
At the bottom of each letter index page is an "Add a new item" form. Enter the term you'd like to add to the glossary into the text box. This will also be the title of the new definition page you are adding. Then click the Add button.
You will be taken to a wiki page create form with the page title already filled in, and the glossary definition template loaded. You can now enter a definition and otherwise edit the page to your liking. Try to stick with the standard format as much as possible to keep the glossary consistent.
Save the page
Remember to save the page to add the glossary term into the glossary.