adds content

Term	Main definition
adds content	Yes that's true :) the definition content is displayed as HTML so the content is indexed in search engines

automatically activated
Yes, a plugin automatically activate tooltip in your content! You can disable it globally or only on a page selection. A click on the word bring you on the definition page.
easy to install
Install it as a package: component, plugins, modules
Entry alias
Using the Joomla default URL rewriting the entry term alias is added to the URL