Applies to: Final Draft 13 / 12 / 11
Final Draft uses the language utilities built into the Windows and Mac operating systems.
The spell-check, thesaurus and user dictionary already on your computer (and which are curated by Microsoft and Apple, respectively) are what Final Draft accesses when you spell-check a word, look for a synonym or add a word to the user dictionary.
When you install an update to your OS and it includes language updates, Final Draft will have all of the new word definitions and slang according to Microsoft and Apple.
If you're in another application and you add a word to your user dictionary, Final Draft (the program) will also know about it.