Lunatic vs. Nutcase — What's the Difference?

Lunatic is an antiquated term referring to a person who is seen as mentally ill, dangerous, foolish, or crazy—conditions once attributed to "lunacy". The word derives from lunaticus meaning "of the moon" or "moonstruck".

A crazy or eccentric person.

A person who is mentally ill (not in technical use).

An eccentric or odd person.

Mentally ill (not in technical use)

Someone who is insane.

A person who is affected by lunacy; a mentally deranged person.

A whimsically eccentric person

A very foolish person.

Affected by lunacy; mentally deranged.

Of or for people who are mentally deranged.

Wildly or giddily foolish

An insane person.

Crazed, mad, insane, demented.

Affected by lunacy; insane; mad; crazy; demented.

Of or pertaining to, or suitable for, an insane person; evincing lunacy; as, lunatic gibberish; a lunatic asylum.

A person affected by lunacy; an insane person, esp. one who has lucid intervals; a madman; a person of unsound mind.

An insane person

A reckless impetuous irresponsible person

Insane and believed to be affected by the phases of the moon