Pop-up Windows via Links in Engage

I've created an Engage slide, process with steps. Within the different steps, I want to create hyperlinks for specific words. So, when a user clicks the hyperlinked word, a window pops up with a definition. I also need to figure out how to close the pop-up window. Is this possible in Articulate? When I click the Hyperlink button in my Engage element, I see that I can hyperlink to other process steps or a URL, neither of which I want to do, I think.