Edit Mispelled Words in Firefox

Firefox keeps a per profile dictionary of custom words. To correct words which inadvertently enter it:

• Go to “%APPDATA%\Mozilla\Firefox\Profiles”
• On Mac OS X, go to “~/Library/Application Support/Firefox/Profiles”
• Enter the profile folder, usually like “.default”
• Edit “persdict.dat” with a text editor (WordPad, Notepad, or Textedit)

Save, and done.