Longman Dictionary of Contemporary English homepage

Date: 1200-1300
Language: Old French
Origin: lunatique, from Late Latin lunaticus, from Latin luna ( LUNAR); because people thought mental illness was caused by the moon

lunatic

noun
     
lu‧na‧tic [countable]
1 someone who behaves in a crazy or very stupid way - often used humorously:
This hotel is run by a lunatic!
2 old-fashioned a very offensive word for someone who is mentally ill:
a dangerous lunatic
3

the lunatic fringe

British EnglishPPG the small group of people in a political group or organization who have the most extreme opinions or ideas
lunatic adjective [only before noun]
lunatic behaviour

Dictionary pictures of the day
Do you know what each of these is called?
What is the word for picture 1? What is the word for picture 2? What is the word for picture 3? What is the word for picture 4?
Click on any of the pictures above to find out what it is called.

Explore our topic dictionary