With the CM Tooltip glossary plugin, you can easily create WordPress tooltip excerpts, allowing your tooltip to only display a quick teaser rather then the complete term definition. The latter is available in the term page which can be accessed by clicking on the term or on the tooltip.
If you want the Tooltip to show only the “Excerpt” of the post instead of the Content within the term page, you need to first set up an “Excerpt” for the term.
Next, you need to check the “Use term excerpt for hover” box, in the plugin’s Settings under the section “Tooltip – Tooltip Content”.
Alternatively, if you want the tooltip to display the first paragraph of your term page unmodified, you can limit the number of characters that appear in the tooltip by entering their amount in the “limit tooltip length” field, which is under the tooltip tab in the plugin settings.