I love finding a resource I used to know about years ago, forgot
   about and then found it again. What usually happens: "Didn't
   there used to be something? Oh yeah!" I look it up only to find
   the service shut down in 2011 or something. But here, OneLook's
   powerful reverse dictionary not only still exists but it's more
   powerful than I remember it being. They also have an interactive
   version and, well, a lot of nice things have interactive
   versions but my interest is things that I can use in batches: in
   this case, having a long list of words I want synonyms for. I
   also want to use their reverse dictionary as well later on, but
   with that the results will take a little more massaging because
   they hacked together their unique reverse dictionary and the
   results are less specific. So, I'm going from specific + certain
   + narrow (Thesaurus) to less specific but more broad (Reverse
   Dictionary). And... I can do it in one place. I love that some
   of the classic Web 2.0 tools are still around: Free endpoints
   available to anybody with no questions asked.
   http://www.datamuse.com/api/ === What is a reverse dictionary?
   http://www.onelook.com/reverse-dictionary.shtml You describe a
   concept and it comes up with plausible words that match. So, if
   you're searching for a word but you can only remember what it's
   about, you type in everything you know and it guesses what you
   might be talking about. They're kind of strange beast: there's
   not many of them available online and only a few ever show up in
   print either, but they're useful for their purpose. It's the
   kind of thing that, with refinements and specificity, becomes
   search engines like google and such.