Firefox, one of the greatest browsers in the world, comes with it’s own built in spell checker to help you ensure that all the words you type are correctly spelled. It won’t help you with grammar, but hey, at least you’ll have your spelling right. ^_^
Firefox also has the ability to add special words to its list of properly spelled words in case you’ve got a proper name you use often, or an alternative spelling of something, that you don’t want to get flagged all the time, or you want spell checked with the rest of the words.
To do that, you’d normally right click on the red highlighted word and select “Add to Dictionary”. However, sometimes in our ever so wonderful gracefulness, we can sometimes add words to the dictionary that are not proper spellings and that we did not want added. So how do you remove those? Well, it’s really quite easy.