It's not ideal, but you can still include Māori words in the dictionary. Keep reading!
In SharePoint 2010, you could add a custom dictionary which would be used by spell check throughout the site. This hasn't changed in SharePoint 2013 and SharePoint Online.
This works per site collection:
- Create a new word document (if you don't require macrons then you can just use notepad to create the .txt file and follow the same steps)
- Add a word to each line, as in the screen shot below
- Save the file as a .txt file named "Custom Dictionary.txt" – this has to be the exact name of the file, select "Other encoding" and set Inicode (UTF-8)
- In the root of your site collection, create a document library named exactly "Spelling"
- Upload your Custom Dictionary.txt file into the document library
The words you added to the dictionary will now be correct spelling.