Restore fonts that came with your Mac
You can restore the fonts that were originally installed on your Mac. This may be useful if you’re having issues with Font Book. Restoring the standard fonts moves any fonts you’ve installed into a separate folder, which makes them unavailable to use in apps.
Choose File > Restore Standard Fonts.
Any fonts you’ve installed are placed in /Library/Fonts (Removed) or in ~/Library/Fonts (Removed). To install those fonts again, just reinstall them.