About a week or so ago, I discovered a free medical spellchecker on GitHub. As I was in the middle of some big translation assignments, I didn’t have the time to properly figure out how to install the spellcheck dictionary on my Mac or in SDL Trados, which is currently my default CAT tool, despite the many drawbacks. Today I finally had some time to catch my breath and figure out how this spellcheck dictionary works.

macOS Installation

Installation on macOS (or Mac OS X, as it was known until recently) is quite simple. The authors of this dictionary have created an installer package, so all you have to do is download Install Package and double-click it to run it. That’s about it!

Of course, this only works for software that uses the system-wide macOS dictionary, so it won’t work in OmegaT out of the box, for example. I’m still trying to figure out how to use it with OmegaT because I’m aiming to move away from SDL Trados.

Windows Installation

Installation on Windows is a tad bit more complicated because Windows doesn’t seem to have a system-wide dictionary like macOS. You’ll have to install the dictionary for Word and Internet Explorer separately. I’m not entirely sure why you would need a medical dictionary in Internet Explorer, but I suppose it could be useful if you use cloud-based CAT tools or a web-based e-mail client in Internet Explorer.

Microsoft Word

If you want to install the spellchecker in Word, just follow these instructions:

  • Download US-English-Medical-Dictionary.dic.
  • Open Word.
  • Click File > Options > Proofing.
  • Make sure the Suggest from main dictionary only check box is cleared.
  • Click Custom Dictionaries.
  • Click Add.
  • Locate US-English-Medical-Dictionary.dic and then double-click US-English-Medical-Dictionary.dic.
  • Open up a document and check spell checking works as you expect.
  • Done!

Source: http://medical-spell-checker-dictionary.github.io/windows/word/

SDL Trados

Installing this in SDL Trados is slightly more complicated than installation in Word, but luckily, I’ve already done the hard part for you!

You can download the Trados-compatible version of the dictionary from my GitHub repository. Once you’ve done that, the process is the same as adding any custom dictionary to Trados.

  • Download the Trados-compatible dictionary file and save it somewhere you’ll remember (e.g. your Desktop).
  • Go to Tools > Options.
  • Select Editor > Spelling from the Options dialog.
  • Click on the Custom Dictionaries button about halfway down the list of options.
  • A new dialog will open. Click on the Add button and browse to the location where you saved the dictionary file and then click Open.

That’s it! Keep in mind that this is for spell checking, so this won’t give you any autosuggestions, unfortunately.

[panel type=”info” heading=”Technical Note”]
If you’re curious about the difference between the “normal” dictionary file format and the one used by Trados, it’s actually quite simple. Trados expects the first line to contain the total number of entries. To figure out the number of lines, I simply used the Unix command [code]wc -l[/code] (which comes with macOS by default) to calculate the number of lines and then added it to the top of the file. You could, of course, do all of this yourself if you’re familiar with the command line or even using a decent text editor, but why reinvent the wheel?


As I mentioned earlier, this dictionary does not provide autosuggestions in Trados. The AutoSuggest dictionary format used by SDL is quite a bit more complicated than the format used for custom dictionaries. Nevertheless, if you work on specialized medical texts, this dictionary will undoubtedly save you a lot of time double and triple checking your spelling! That being said, you may still want to double check some of these entries as I have not verified their accuracy.

Do you use custom dictionaries as part of your translation workflow? Do you know how to use custom dictionaries in OmegaT or other CAT tools? I’d love to hear about any other dictionaries you’ve found, especially if they’re free and open source. I’d also be very interested in learning how to use custom dictionaries in OmegaT or how to create an AutoSuggest dictionary for SDL Trados. Let me know in the comments section if you have any ideas or if you think I’ve gone about this the wrong way and have ideas on how to improve installation.

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