rich: n. Laden with useless features and incredibly difficult to use in real life.

Example:

“ZK is a Web framework designed to enable Web applications to have both rich user experiences and a simple programming model. ZK includes an AJAX-based event-driven engine to automate interactivity, a rich set of XUL and XHTML components to enrich usability”

Translation: ZK has a boatload of components which you will never use; those you do, will be incredibly hard to program even though they include basically text fields, buttons and checkboxes; and all this will result in a molasses-slow experience for your end-user.