This didn't do anything at all and I didn't receive any messages. I'm now worried about what I might have installed instead.

I use this all the time, because they used to call me Mr. Vocabulary, but now I know there's a word, but I can't think of what it is.

Type a word, get a list of synonyms. It's a simple concept, but that's all I need or want from this extension. Five stars!

If this great product has stopped working for you, see BDev's instructions below. They really work, and now (after months of frustration) the add-on does too! Hooray!

Server not found.

Points to non-existent domain name "http://thesaurus.reference.com".

Thanks for the fix, BDev! Have always loved this add-on and was sad that it hadn't worked for several months. Now I'm back in business!

To BDev:
It worked for me too! Thanks so much for posting the fix! :)

BDev's instructions below fixed the problem. Thank you.

To BDev:
It worked! Thanks for posting the fix.

This was a GREAT search tool, but it stopped working about a month or two ago. I tried it again today, but it just says, "Unable to Connect."

This worked for me:
1) Delete the bad Thesaurus - Reference.com search engine from you list of engines.
2) Go to the developer's website here: http://gooeysoftware.com/mozaddons/search/
3) Left-click the Thesaurus - Reference.com link. This should automatically add a new Thesaurus search engine to your list; with the correct URL pointer.

For a while now I've been receiving an 'Unable to connect' message.

I love this plugin, I use it every single day, but it needs to be updated to point to thesaurus.com rather than thesaurus.reference.com. There's a quicker fix, however, than searching for a file on Google.

Go to Preferences, then Search and find your search engine list. Highlight 'Thesaurus - Reference.com' and click on 'export to file...' Save the file to your desktop and open it with a simple text editor. Change all references to 'thesaurus.reference.com' to 'thesaurus.com" and then import that file into your search engine list in Preferences (using the 'Import Search Engines From Files..' option.

You'll end up with 2 Thesaurus search engines, so delete the old one ('Thesaurus - Reference.com') and leave the new one: Thesaurus.com.
:-)

It needs to point to 'thesaurus.com' I installed this on a default FF52 profile and it pointed to the defunct address. I was able to work around by changing all references to 'thesaurus.reference.com' to 'thesaurus.com' in the old XML file: "thesaurus.xml" (still available, google it). I then used the "XML Search Engines Exporter/Importer" addon to import the XML file to the search.json.mozlz4 file. Works like a charm. If it gets updated I will change the 3-star to a 5-star.

www.thesaurus.com is apparently no longer part of the reference.com family, since thesaurus.reference.com is no longer accessible.

The below reviewer (Op4) is incorrect—it still works perfectly. I'm using Firefox 50 in the year 2017 and it worked instantly and beautifully. It brings up thesaurus.com when you use it.

The best part is this isn't even an "addon". When you click "Add to Firefox", it just gives you a quick pop-up asking if you want to add it to your list of Firefox search engines. Then it's ready to go!

Can't wait to see what the new synonyms of "Trump" will be over the next year.

This one is yet another underrated winner. BTW: it works perfectly fine on a superior browser: PaleMoon.

Im using the latest version of FF, 39 and this is the error I am recieving when trying to install: Sorry, you need a Mozilla-based browser (such as Firefox) to install a search plugin.
Boo! Not good... I really wanted to use this

This is exactly the plug I've been needing.
However, I just reinstalled Windows + Mozilla on this comp, and when I try to download the plug in, it tells me that I have to have a Firefox browser...which I was/am using. It most likely doesn't have anything to do with the plug in, but I thought I'd put it out there. Thanks for the great search addition, hope to be using it again soon.

Thanks. mozdev is currently updating bugzilla but that didn't stop me from finding synonyms on the fly! Victory to the supreme expression of Open Source. My obeisances to all who form the new paradigm of omniscient data.

Works seamlessly and speedily. Good job!

Works a treat. Lets me have access to a Thesaurus.

Works great. Very useful.