Question: I experience reoccurring incidents of `fontd` eating up all the process power. What could be the cause of this and how do I make it behave again?

Answer: 
`sudo atsutil databases -remove; atsutil server -shutdown`

From 50% cpu usage to 1%

Source: <http://icicity.com/2014/02/13/high-cpu-usage-caused-by-fontd-on-os-x>
Do [the following](https://support.apple.com/guide/font-book/restore-fonts-that-came-with-your-mac-fb34862/mac) and place your removed fonts back to the "font" folder of your library folder.

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> Restore fonts that came with your Mac using Font Book
> You can restore the fonts that were originally included with 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.
> 
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> In the Font Book app on your Mac, choose File > Restore Standard Fonts.
> 
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> Any fonts you’ve installed are placed in /Library/Fonts (Removed) or in ~/Library/Fonts (Removed). To install those fonts again, just reinstall them.
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