From several species of tree in the genus Myristica, Nutmeg is a spice. [Source]
A similar spice to nutmeg is mace which is made up of dried lacy reddish covering or aril of that seed.
So can cats eat nutmeg?
No, it is not recommended that you feed nutmeg to your cat.
Nutmeg isn’t really toxic to cats in small amounts but in large quantities it can cause your cat to have diarrhea and vomit.
Therefore if your cat was curious and had a lick or two of nutmeg they should be fine but you shouldn’t purposely be feeding nutmeg to them.