On the Atlas Glossary page, click Category. Select a category,
then click the + symbol next to the "Terms:"
label on the Category page.
On the "Assign term to Category" pop-up, select a glossary term. To
filter the list of terms based on a text string, type the text in the
"Search Term" box. The list is filtered dynamically as you type to
display the terms that contain that text string. Click Assign to assign the term to the
category.
The new category appears next to the "Terms:" label on the Category
page.