I am using MacOS and need to write documents which use a lot of medical terminology. Currently, the system detects many of these words as being incorrectly spelled (even when they are not), or invalid (when they are), and the various Autocorrect, Autocomplete, Spell Checker, and the system Dictionary all regularly try to "correct" these words, or, because they don't actually know which word I'm trying to write, cannot help me write them correctly.
I want to do more than just tell the OS to ignore these. While improper auto-corrections can be a big problem, the red underlines everywhere are very annoying as well.
I need to use these words throughout MacOS, on Mail, Messages, Calendar, Notes, Reminders, Safari, Stickies, and also in 3rd party apps running on MacOS, such as MS Office and the Chrome browser.
How can I bulk import words or entire dictionaries into the MacOS dictionary such that those words will be used by the system for auto-correction, auto-completion, spell-check, and other helpers the OS tries to provide?
I suppose related to this is the question of whether these 3rd party apps use the OS-wide dictionary or not. I do not know whether this is the case.
This is a significant problem to me, and I am willing to try just about anything to solve it, including learning Terminal if I must.