Rated 5 out of 5 stars

This is a good add-on. I had no issues with it not opening the definition page for the word I selected. As a writer, I have used m-w.com as an online dictionary for years after finding discrepancies and errors using other dictionaries. Yes, they do have ads and registered services to offer, but that is a small inconvenience to suffer for the volume of free and ACCURATE information they offer. My only regret is waiting so long to get this add-on.

This review is for a previous version of the add-on (20080326).