OneLook’s reverse dictionary lets you describe a concept and get back a list of words and phrases related to that concept. Your description can be a few words, a sentence, a question, or even just a single word. Just type it into the box above and hit the “Find words” button. (Keep it short to get the best results.) In most cases you’ll get back a list of related terms with the best matches shown first.
You can use this to look up what the name of that little nub on the end of your shoelace is called, use it as a thesaurus, generate a list of words in a category such as Canadian authors or identify the longest river in the world.
I found this particular reverse dictionary a little cumbersome in that you have to click three times to find out if the word you chose is the correct one, but it’s still more useful than the paper version I have on a shelf at home!
However, the most useful part of this site is the wildcards. With some creative wildcard use, you can have it help you spell words! For instance, I always have to think about how many Cs are in recommend, so I typed in rec*end and was rewarded with the correct spelling! Not sure how many Ms and Rs are in tomorrow? Type in to*ow and there you are!