Rated 3 out of 5 stars

The idea is great, I love being able to look up words, and as a contributor to Wiktionary, it's really amazing that the information comes from there. I find the interface quite awkward though, and would prefer the option to ctrl+click or alt+click on the word and then be able to move my mouse while it loads.

This review is for a previous version of the add-on (1.2.1). 

WikiLook

Sure, in the future this add-on will be way more customizable. But Ctrl+click or Alt+click is not really an option because Firefox do use thous shortcuts for popular and well defined functions.