Keywords are one powerful feature in D2H which help in organizing topics better; however, they come with one little, extra step of explicitly creating and adding them in the project.

In case you want to do away with this overhead, all you need to do is define ‘AutoIndex’ for the style.

Here are the steps to do the same:
1) Go to Project tab -> Auto Index
2) Select the style for which you want Keywords to automatically be generated, say: ‘Glossary Term Definition’
On rebuilding the project, ‘Keywords’ will automatically be generated for all the Glossary Terms inside the project.

Please refer to the image below:

I am attaching a project along with the post. Download and open the project.
Observe that ‘Glossary Term Definition’ has been selected in ‘AutoIndex’ menu under ‘Project’ tab.
On rebuilding, the same Keywords will automatically be generated for the added ‘Glossary Term Definitions’ inside the project.