lunatic

adjective
lu·​na·​tic | \ ˈlü-nə-ˌtik How to pronounce lunatic (audio) \

Definition of lunatic

1 dated
a : affected with a severely disordered state of mind : insane
b : designed for the care of mentally ill people a lunatic asylum
2 : wildly foolish a lunatic idea lunatic behavior

Other Words from lunatic

lunatic noun

Synonyms & Antonyms for lunatic

Synonyms

Antonyms

Visit the Thesaurus for More 

Examples of lunatic in a Sentence

He hatched a lunatic plot to overthrow the government. another of his lunatic ideas
Recent Examples on the Web Having long since given up on reigning in the enormous lunatic wing of their party, Republican leaders had, particularly after the rise of Donald Trump, began actively catering to it. Alex Shephard, The New Republic, 20 Apr. 2022 The point of such a response would be to portray the Democrats as the reasonable party upholding moderation and decency in the face of a lunatic assault on the rights and freedoms of the female half of the population. Damon Linker, The Week, 1 Apr. 2022 After the trial, Tyler was sent to lunatic asylum [sic] receiving psychological treatment. Patrick Frater, Variety, 7 Feb. 2022 After the trial, Tyler was sent to lunatic asylum [sic] receiving psychological treatment. Patrick Frater, Variety, 7 Feb. 2022 Marjorie Taylor Greene, the lunatic Georgia MAGA congressman who only recently stopped loving QAnon and thinks that Jewish space lasers might be starting wildfires out west, is one of the right’s biggest stars. Alex Shephard, The New Republic, 28 Feb. 2022 After the trial, Tyler was sent to [a] lunatic asylum receiving psychological treatment. Michelle Toh, Nectar Gan, And Cnn's Beijing Bureau, CNN, 7 Feb. 2022 After the trial, Tyler was sent to lunatic asylum [sic] receiving psychological treatment. Patrick Frater, Variety, 7 Feb. 2022 After the trial, Tyler was sent to (a) lunatic asylum receiving psychological treatment. Bryan Alexander, USA TODAY, 27 Jan. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'lunatic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of lunatic

14th century, in the meaning defined at sense 1a

History and Etymology for lunatic

Middle English lunatik, from Anglo-French or Late Latin; Anglo-French lunatic, from Late Latin lunaticus, from Latin luna; from the belief that lunacy fluctuated with the phases of the moon

Learn More About lunatic

Time Traveler for lunatic

Time Traveler

The first known use of lunatic was in the 14th century

See more words from the same century

Dictionary Entries Near lunatic

lunately

lunatic

lunatically

See More Nearby Entries 

Statistics for lunatic

Last Updated

23 Apr 2022

Cite this Entry

“Lunatic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lunatic. Accessed 26 May. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for lunatic

lunatic

adjective
lu·​na·​tic | \ ˈlü-nə-ˌtik How to pronounce lunatic (audio) \

Kids Definition of lunatic

 (Entry 1 of 2)

lunatic

noun

Kids Definition of lunatic (Entry 2 of 2)

1 : an insane person
2 : a person who behaves very foolishly That lunatic went through a red light.

lunatic

noun
lu·​na·​tic | \ ˈlü-nə-ˌtik How to pronounce lunatic (audio) \

Medical Definition of lunatic

dated, now offensive : an individual marked by a severely disordered state of mind

lunatic

noun
lu·​na·​tic | \ ˈlü-nə-tik \

Legal Definition of lunatic

: an insane person used especially formerly

Other Words from lunatic

lunatic adjective

More from Merriam-Webster on lunatic

Nglish: Translation of lunatic for Spanish Speakers

Britannica English: Translation of lunatic for Arabic Speakers

WORD OF THE DAY

Test Your Vocabulary

Eponyms: Words Named After People

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!