The Moodle Glossary sometimes causes a few glitches, especially when you want to use the very effective Autolinking feature.

Autolinking is a feature which highlights words in the Glossary, whenever they appear on text stored within Moodle. This means text loaded into Web Pages, Lesson Module text, forum postings, summaries etc. It does not work with uploaded documents such as PDF, and Word Documents.

To make Autolinking work you must follow these steps:

1. In the Glossary Configuration, enable Autolinking .
2. Each Glossary item needs to be set to enable Autolinking .
3. In the Site Administration Menu, navigate to Modules -> Filters -> Manage Filters, and enable Glossary Autolinking .

Note that if you do not want particular text to be linked (in a forum posting, say) then you should add <nolink> and </nolink> tags around the text.

For more on the Glossary Module visit the Moodle Docs site.