What's a lunatic? Is it a mental dis-order?

Question

What's a lunatic? Is it a mental dis-order?

Answer 1

The word lunatic is a word that somebody may call someone.

In my dictionary it means insane.

Answer 2

The term "lunatic" comes from a latin derivative meaning "of or relating to the moon".   The original idea hundreds of years ago was that different phases of the moon triggered very odd behavior in people.  Most of it would probably qualify as mass hysteria today, but some people might have actually had some psychotic disorder.

The term isn't really used today, at least in a scientific sense.  If someone is called a "lunatic" it might just mean that they act in a way that doesn't conform with society's standards, but it could also be misused to mean that an individual does have an apparent mental disorder.