If you have ever mistakenly added a word to the Brave browser dictionary,
you need to manually edit the Custom Dictionary.txt
file.
As of March 2020, the Brave UI lacks a feature to do this.
This will depend on your OS. Google for where this is on your OS.
The file on macOS is at: ~/Library/Application\ Support/BraveSoftware/Brave-Browser/Default/Custom\ Dictionary.txt
.
Use your favorite text editor to edit and save the file.
There's a checksum on the final line, does that need to be changed? I removed the accidentally added dictionary item, but it doesn't seem to do the red squigglies in the UI anymore.