How to Add a Custom Dictionary in Word

Microsoft Word’s built-in spell checker is an invaluable tool for catching typos, but it can quickly become frustrating if you work in a specialised field. If your documents frequently contain medical terminology, legal jargon, specific brand names, or unique character names for a novel, Word will stubbornly underline them in red, flagging them as errors. By adding a custom dictionary, you can train Word to recognise your specific vocabulary, eliminating false alarms and ensuring you only see red lines for genuine mistakes.

Why Use a Custom Dictionary?

While you can right-click a flagged word and select “Add to Dictionary,” those additions are saved to your default roaming dictionary. If you need to enforce a specific style guide for a client project, or if you share a computer and do not want your technical jargon polluting a colleague’s spell checker, creating a separate, dedicated custom dictionary is the professional solution. You can toggle these custom dictionaries on and off depending on which project you are currently working on.

Step-by-Step: Adding a New Custom Dictionary

Creating and activating a new dictionary is done through Word’s advanced proofing settings.

1. Open Microsoft Word.
2. Click on the File tab in the top-left corner.
3. Select Options at the very bottom of the left-hand menu.
4. In the Word Options dialogue box, select Proofing from the left sidebar.
5. Under the section titled “When correcting spelling in Microsoft Office programs”, click the Custom Dictionaries… button.
6. A new window will appear listing your current dictionaries. Click the New… button.
7. Word will prompt you to save a .dic file. Give your dictionary a descriptive name (e.g., “Medical_Terms.dic” or “Client_Project.dic”) and click Save.
8. Your new dictionary will now appear in the list. Ensure the checkbox next to it is ticked so it remains active.
9. Click OK on all open dialogue boxes to return to your document.

How to Manually Add or Remove Words

Once your dictionary is active, any word you right-click and select “Add to Dictionary” will be saved. However, you can also bulk-add words or remove mistakes manually.

1. Return to File > Options > Proofing > Custom Dictionaries…
2. Select your newly created dictionary from the list (ensure it is highlighted).
3. Click the Edit Word List… button.
4. To add a word, type it into the “Word(s):” field at the top and click Add.
5. To remove a word you accidentally saved, find it in the list, select it, and click Delete.

Troubleshooting Common Mistakes

If your custom dictionary does not seem to be working, check these common configuration errors:

• The wrong default dictionary: When you right-click a word and select “Add to Dictionary” while writing, Word saves it to whichever dictionary is set as the default. If you created a new dictionary but words are not saving to it, go back to the Custom Dictionaries menu, select your new dictionary, and click the Change Default button.
• Language mismatches: Custom dictionaries are often tied to specific languages. If your document is set to UK English, but your custom dictionary was created under a US English setting, Word will ignore your custom words. In the Custom Dictionaries menu, look at the “Dictionary language” drop-down at the bottom. If it is set incorrectly, you must select “All Languages” to ensure Word checks it regardless of the document’s regional settings.

By effectively managing custom dictionaries, you can streamline your proofreading process and ensure your technical documents are perfectly spell-checked without the visual clutter of false errors.