This system-wide, built-in dictionary is used by Apple’s entire suite of apps, plus many third party applications, so once you’ve added a word you’ll typically find that most programs stop complaining about that word, and will never attempt to autocorrect it again.Īnd just in case you slip up and add a word that’s spelt incorrectly, or that contains a typo, I’ll also be showing you how to remove words that you’ve added to macOS’ dictionary. If it’s starting to feel like you’re fighting against your Mac’s spellchecker, then in this article I’m going to show you how to quickly and easily add words to macOS’ dictionary. If you regularly type unusual brand or product names, technical terms, foreign words, or other “niche” terms, then at best, your Mac will keep underlining these words, but at worst it’ll step in and attempt to autocorrect these “mistakes.” Your Mac’s built-in spellchecker can be an invaluable tool for catching spelling mistakes and typos, but if you regularly type words that aren’t in your Mac’s dictionary, then macOS’ spellchecking functionality can actually make typing more difficult.