First of all, I hate to go back to work. It really cramps my blogging time, but I do it whenever I can.
You have a private spelling on your Mac, where you can save unusual spelling or words that you use frequently. For example, I always add Gravley to my because spell checking tends to change it to serious. Spell checking uses New Oxford American Dictionary as spell check source.
When spell checking a word is misspelled, it will emphasize it in red. To add that word to your private directory, just right-click and choose Learn Spelling.
If you find that you have saved a word that is misspelled, you can remove it. Here's how.
In the Finder window select Shift + Command + G .
A small window named Go to Folder opens. Enter ~ / Library / Spatial Mode in the text field and press the Go button.
This will take you to the library mail folder.
Select the local book folder. This takes you to your local dictionary file which is a single text editor document. Check your words and delete any words (and empty spaces) that need to be removed.
Now you are safe from your own feet. Until you do it again. Do not hurt to check it once in a while.