A huge number of current rude terms have medical origin, including an entire measured scale, including idiot, as you called out:
Moron (from Wikipedia):
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It was once applied to people with an IQ of 51–70, being superior in one degree to "imbecile" (IQ of 26–50) and superior in two degrees to "idiot" (IQ of 0–25). The word moron, along with others including "idiotic", "imbecilic", "stupid", and "feeble-minded", was formerly considered a valid descriptor in the psychological community, but it is now deprecated in use by psychologists.
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Similarly cretin as someone with congenital iodine deficiency syndrome, but now far less polite and just generically dumb.
The list misses huge numbers of terms. It feels very much like a small group of people sat down and brainstormed for 5 minutes writing out the things that bothered them individually, or knew about individually, and that was it.
Moron (from Wikipedia): --- It was once applied to people with an IQ of 51–70, being superior in one degree to "imbecile" (IQ of 26–50) and superior in two degrees to "idiot" (IQ of 0–25). The word moron, along with others including "idiotic", "imbecilic", "stupid", and "feeble-minded", was formerly considered a valid descriptor in the psychological community, but it is now deprecated in use by psychologists. ---
Similarly cretin as someone with congenital iodine deficiency syndrome, but now far less polite and just generically dumb.
The list misses huge numbers of terms. It feels very much like a small group of people sat down and brainstormed for 5 minutes writing out the things that bothered them individually, or knew about individually, and that was it.