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.