Where does “moron” come from?

Moron comes from Ancient Greek μωρός, from Proto-Indo-European muHrós, meaning a person of low intelligence or foolishness.

moron (English): A stupid person; an idiot; a fool; A person of...

Definitions

Step	Language	Word	Meaning
1	Ancient Greek	μωρός	slow, sluggish; slow, dull, foolish, stupid;...
2	Proto-Indo-European	muHrós	dull, stupid

moron — Etymology, Origin & Word History | Etymology Explorer