Rated 5 out of 5 stars

Compared to similar add-ons, WikiLook has the best content (including photos), user interface display, ease of access, options within a word's definition (i.e. hyperlinks), and linking other subject-matter that relates to the word. The one thing that I like most about this add-on is how it uses javascript to allow you to preview "more" about the definition without redirecting you to another site. Instead, it just drops-in more information into the display box, all on the fly.