How To Save Words In Dictionary On Mac | Fix Spelling Flags

If your Mac keeps putting a red underline under a name, acronym, brand term, or local spelling, you don’t need to fight it each time you type. Save that word once, and in many apps your Mac will stop treating it like a mistake.

The part that trips people up is the word “dictionary.” The Dictionary app is built for lookups. The list that handles spell checking lives in typing and app settings.

Why Your Mac Keeps Rejecting A Word

Mac spell check works from a language list. When a word doesn’t match that list, macOS flags it. That can happen even when the word is correct. Last names, medical terms, slang, product names, place names, and mixed-language writing all run into this.

• Your word belongs to a different English variant, such as “colour” or “organise.”
• You type initials or brand names in a style the spell checker doesn’t know.
• You need the same custom word in Pages, Notes, Mail, and TextEdit.
• You want a shortcut that turns a short code into the full word each time.

Sometimes you don’t just want the underline gone. You want the Mac to help you type the word faster and in the same form each time. Text Replacements handle that better than the normal spelling list.

How To Save Words In Dictionary On Mac In Three Ways

Method 1: Add The Word From Spell Check

This is the cleanest route when your Mac marks a word as wrong inside an app that uses the macOS spelling system. Pages is a clear example. Apple says the spelling window lets you add terms to the Mac dictionary used by Pages and other apps through the Pages spelling window.

1. Type the word exactly the way you want it to appear.
2. Control-click the underlined word.
3. Choose the option that adds the spelling, if the app shows it.
4. In Pages, you can also press Command-Semicolon to move to the flagged word, then add it from the spelling controls.

Once that word is stored, the red underline usually disappears the next time macOS checks it. This works well for names, place names, and one-off terms.

When This Method Fits Best

Pick this route when you want the word accepted, not changed. You’re telling your Mac, “This spelling is fine. Leave it alone.”

Method 2: Add A Text Replacement

Text Replacements are a smart pick when you type the same unusual word over and over. Apple’s page on Text Replacements on Mac shows where to add them.

1. Open System Settings.
2. Click Keyboard.
3. Under Text Input, click Edit.
4. Press the plus button.
5. Enter a short trigger in Replace.
6. Enter the full word in With.
7. Click Done.

Say you type “brndx” and want it to become “BrandX.” Or you type a short code and want a full surname with accent marks to appear. That saves time and keeps the spelling steady across notes, drafts, and email.

Method 3: Set The Right Spelling Language

Some words get flagged only because your Mac is checking them against the wrong language. Apple’s page on typing suggestions and autocorrection settings pairs well with switching the spelling language in Keyboard settings.

1. Open System Settings.
2. Go to Keyboard.
3. Find the Spelling menu.
4. Choose the language you write in most, or choose Automatic by Language.

If you write in British English, American English, and another language on the same Mac, this change can cut down false flags before you add a single custom word.

Saving New Words To Your Mac Dictionary Without The Red Underline

Adding a word through spell check tells macOS to accept that word, while Text Replacements tells macOS to swap one typed string for another. Both can solve the same annoyance, but they solve it in different ways.

Method	Best For	What Happens
Add From Spell Check	Names, jargon, place names	Mac accepts the typed word and stops flagging it in many apps.
Text Replacement	Long custom terms	A short trigger expands into the full word or phrase.
Automatic By Language	Mixed-language writing	Mac checks words against the matching language where it can.
App Ignored Words List	One app only	The app stops marking that word wrong inside that app.
Unlearn Spelling	Wrong custom entry	Mac removes the saved spelling and flags it again later.
Consistent Capitalization	Brand names and initials	Mac is less likely to treat each version as a new word.
One Saved Form Per Word	Words with accents or symbols	You avoid storing several near-matches that create clutter.

If you’re dealing with one stubborn word, add it from spell check first. If you type that word all day, build a text replacement. If half your draft is getting marked wrong, check the language menu first.

Pages can store ignored words for Pages documents, while the macOS spelling dictionary reaches across other apps too. If a word behaves one way in Pages and another in Notes, that split is often the reason.

What Gets Saved, And Where It Shows Up

Most people expect one master dictionary. macOS is a bit messier than that. You’re working with a few layers:

• System spelling dictionary: accepted custom spellings used by many Mac apps.
• Text Replacements: shortcuts that expand into full text.
• App ignored words lists: words one app leaves alone.

That means a saved word may appear fixed in Pages and still act odd in a third-party app with its own editor. If that happens, the app may not be using Apple’s spelling tools in the same way.

If you save “AcmeData” in one place, “Acmedata” in another, and build a shortcut for “acmed,” you can wind up with mixed results. Pick one form and stick to it.

Common Snags And The Fix

When a saved word still gets underlined, the cause is usually small: the wrong language, a different app engine, or a saved form that doesn’t match what you typed.

Problem	Likely Cause	Fix
The word is still underlined in one app	The app uses its own spell checker	Add it inside that app too, or use a text replacement.
The word works in Pages but not Notes	The word was ignored in one app only	Add it to the system spelling list, not just the app list.
The wrong spelling keeps returning	Autocorrection is changing it	Turn off autocorrection for that workflow or add a replacement.
British spelling gets flagged	Language is set to U.S. English	Switch spelling to the right variant or use automatic detection.
A shortcut does nothing	Text replacement is off in that app	Check the app’s Edit menu and system keyboard text settings.
You saved the wrong word	A bad custom entry is stored	Use Unlearn Spelling, then add the correct version.

If you share your Apple Account across devices, some text substitutions can show up on your other Apple gear too. That’s handy when your Mac and iPhone need the same names or work terms.

What Not To Do When A Word Looks Wrong

• Don’t save three spellings of the same word with tiny case changes.
• Don’t build a text replacement when you only need the red underline gone once.
• Don’t ignore the language menu if lots of normal words are getting flagged.
• Don’t assume the Dictionary app is the place to edit spell-check entries.

The Dictionary app is great for definitions. It just isn’t the control room for custom accepted spellings.

A Clean Setup That Sticks

Start small. Add single custom words through spell check. Build Text Replacements only for words you type all the time. Set your spelling language once so the Mac stops fighting the way you already write.

Then test the word in two or three apps you use each day. If one app still acts up, the fix is usually inside that app’s own spelling menu, not your whole Mac.

That’s the real trick to saving words on a Mac: you’re choosing the right tool for the type of word you want to keep.