lunatic

adjective
lu·​na·​tic | \ˈlü-nə-ˌtik \

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

Keep scrolling for more

Other Words from lunatic

lunatic noun

Synonyms & Antonyms for lunatic

Synonyms

balmy, barmy [chiefly British], bats, batty, bedlam, bonkers, brainsick, bughouse [slang], certifiable, crackbrained, cracked, crackers, crackpot, cranky [dialect], crazed, crazy, cuckoo, daffy, daft, demented, deranged, fruity [slang], gaga, haywire, insane, kooky (also kookie), loco [slang], loony (also looney), loony tunes (or looney tunes), mad, maniacal (also maniac), mental, meshuga (or meshugge), moonstruck, non compos mentis, nuts, nutty, psycho, psychotic, scatty [chiefly British], screwy, unbalanced, unhinged, unsound, wacko (also whacko), wacky (also whacky), wud [chiefly Scottish]

Antonyms

balanced, compos mentis, sane, sound, uncrazy

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

Robin Williams had the same thing going for him: a lunatic brilliance that none of his movies ever truly utilized effectively. Soren Andersen, The Seattle Times, "‘The Spy Who Dumped Me’: Kate McKinnon makes familiar action comedy something special," 30 July 2018 Which, according to some lunatic math, saves you two pounds a year. Samantha Leal, Marie Claire, "Blotting Your Pizza with a Napkin Is a Lie," 1 Oct. 2015 The indelible writer, actress, lunatic cabaret star and occasional solo performer Erin Markey comes to the Bushwick Starr with a two-hander, co-starring her friend Emily Davis. Alexis Soloski, New York Times, "11 Plays and Musicals to Go to in N.Y.C. This Weekend," 17 May 2018 Amanda Peet says her house often resembles a lunatic asylum. Jessica Gelt, latimes.com, "Amanda Peet, playwright: How the actress became the author of the Geffen's upcoming premiere," 13 June 2018 Nick Drnaso's new graphic novel, Sabrina (Drawn & Quarterly), is a subtle, heart-wrenching, multifaceted look at loneliness and loss in our lunatic asylum of a country and an impressive follow-up to his 2016 debut, Beverly. Mark Peters, Chicago Reader, "Nick Drnaso’s second graphic novel, Sabrina, examines the perils of living too long in your own head," 22 May 2018 Only a minute remained of the second leg of this Champions League semifinal, sixty more seconds after three frantic, chaotic, lunatic hours of soccer over two games. Rory Smith, New York Times, "Champions League: Liverpool Ousts Roma in Loss That Doubles as a Triumph," 2 May 2018 The indelible writer, actress, lunatic cabaret star and occasional solo performer Erin Markey comes to the Bushwick Starr with a play for two, co-starring her friend Emily Davis. Alexis Soloski, New York Times, "9 Plays and Musicals to Go to in N.Y.C. This Weekend," 10 May 2018 Argentina’s economy had been battered by the lunatic policies of a succession of populist governments. The Economist, "Argentina’s economic woes," 10 May 2018

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.

See More

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

Keep scrolling for more

Learn More about lunatic

Dictionary Entries near lunatic

lunas

lunate

lunately

lunatic

lunatically

lunatic fringe

lunation

Statistics for lunatic

Last Updated

17 Nov 2018

Look-up Popularity

Time Traveler for lunatic

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

See more words from the same century

Keep scrolling for more

More Definitions for lunatic

lunatic

adjective
lu·​na·​tic | \ˈlü-nə-ˌtik \

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

Medical Definition of lunatic 

: 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

Keep scrolling for more

More from Merriam-Webster on lunatic

Rhyming Dictionary: Words that rhyme with lunatic

Thesaurus: All synonyms and antonyms for lunatic

Spanish Central: Translation of lunatic

Nglish: Translation of lunatic for Spanish Speakers

Britannica English: Translation of lunatic for Arabic Speakers

Comments on lunatic

What made you want to look up lunatic? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to make faulty or ineffective

Get Word of the Day daily email!

Test Your Vocabulary

Late Autumn 2018 Words of the Day Quiz

  • frosted-autumn-leaves
  • Which is a synonym of yahoo?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

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!