How do i remove a stadard word from a spell check dictionary?

Question

even thought its a real word and spelled correctly i want to be highlighted if i type it.
I'm using the standard English(united states) dictionary.
i also have low technical skill.
i meant to type "dog" but i actually typed "dong" and it lead to some embarrassment , i want it to remove it as a standard word from my spellchecker , Ive got a few I'm thinking of removing , as a just in case kind of thing.
Thanks guys

Answer 1

Yes, editing that file works. Because the line breaks are not traditional DOS line breaks, you should not use Notepad as your editor. Instead, try this:
(1) With Firefox closed, open the Start menu to All Programs > Accessories
(2) Right-click Wordpad and choose Run as Administrator, give yourself permission when prompted by Windows
(3) Navigate Wordpad's Open dialog to C:\Program Files (x86)\Mozilla Firefox\dictionaries and change the file type to all files (or type *.* in the box and press Enter) so you can open en-US.dict
(4) Search in the page (Ctrl+f) for dong/ (it's not the first one) then add XYZ between dong and /
''The reason for this is so you can easily find and undo your changes by searching for XYZ/ or globally replacing that back to / if needed.''
(5) Save and then restart Firefox. If spellcheck seems to work correctly, you can close Wordpad. If not, you might want to undo your changes in Wordpad (you might or might not be able to save that with Firefox open).