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Synonyms

cuckoo

American  
[koo-koo, kook-oo] / ˈku ku, ˈkʊk u /

noun

  • cuckoos
    plural
  1. a common European bird, Cuculus canorus, of the family Cuculidae, noted for its characteristic call and its brood parasitism.

  2. any of several other birds of the family Cuculidae.

  3. the call of the cuckoo, or an imitation of it.

  4. Slang. a crazy, silly, or foolish person; simpleton.


verb (used without object)

cuckooed, cuckooing
  1. to utter the call of the cuckoo or an imitation of it.

verb (used with object)

cuckooed, cuckooing
  1. to repeat monotonously.

adjective

  1. Slang. crazy; silly; foolish.

  2. of, relating to, or like a cuckoo.

cuckoo British  
/ ˈkʊkuː /

noun

  1. any bird of the family Cuculidae, having pointed wings, a long tail, and zygodactyl feet: order Cuculiformes. Many species, including the European cuckoo ( Cuculus canorus ), lay their eggs in the nests of other birds and have a two-note call

  2. informal an insane or foolish person

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. informal insane or foolish

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

interjection

  1. an imitation or representation of the call of a cuckoo

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (tr) to repeat over and over

  2. (intr) to make the sound imitated by the word cuckoo

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
cuckoo Idioms  

Other Word Forms

Noun Inflected Forms


Etymology

Origin of cuckoo

1200–50; Middle English cuc ( c ) u, cuccuk ( e ) (imitative); compare Latin cucūlus, French coucou, German Kuckuk, Dutch koekoek, Modern Greek koûko


Explanation

A cuckoo is a type of long-tailed bird that's known for laying its eggs in the nests of other birds. In the summer, you're most likely to see cuckoos in various parts of Europe. The famous German cuckoo clock is named for the cuckoo bird, and the cuckoo sound the clock makes each hour imitates the call of the cuckoo. To make this call is also to cuckoo. Informally, you might refer to eccentric or crazy people or situations as cuckoo. Though this informal meaning is credited to American English, the word has been used to mean "stupid person" since at least the 1580s.

Keep Reading on Vocabulary.com

Vocabulary lists containing cuckoo

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

Why is everyone so cuckoo about the Rams?

From The Wall Street Journal ● Sep. 8, 2026

My favorite depictions of this city know its real history is too cuckoo to capture sincerely; straight reenactments make the production of 35mm masterpieces look as piddly as Shrinky Dinks.

From Los Angeles Times ● Jul. 1, 2026

If you rode your horse to that one, you know what a cuckoo series that was.

From The Wall Street Journal ● Jun. 10, 2026

And that has momentum traders going cuckoo for qubits.

From Barron's ● May 29, 2026

Mr. Barris admits that he has been attempting to track him down for some time after admiring several Thiessen-crafted cuckoo clocks, and was pointed in the right direction by a local shopkeeper.

From "The Night Circus" by Erin Morgenstern

Among the more poignant moments, Charles laments the loss of wildlife at Highgrove, noting when he first moved in there nearly five decades ago he would hear cuckoos and see grasshoppers.

From Barron's ● Jan. 28, 2026

These efforts have helped protect a refuge for birds including willow flycatchers and yellow-billed cuckoos.

From Los Angeles Times ● May 26, 2024

There are two variants of female cuckoos: a gray morph that looks like a sparrowhawk, and a rufous morph.

From Science Daily ● Apr. 24, 2024

Pigeons, meanwhile, which were originally thought to be cousins with flamingos, belong to an entirely different branch and actually bear a much stronger genetic resemblance to cuckoos.

From Science Magazine ● Mar. 31, 2024

That meant Lady Constance had eight full cuckoos to build up a head of steam.

From "The Hidden Gallery" by Maryrose Wood

When the BBC visited the London properties with the Met police, officers said squalid conditions were the norm when it comes to cuckooed premises.

From BBC ● Jun. 8, 2026

She said she was cuckooed for months, and became "a prisoner in my own home".

From BBC ● Jun. 8, 2026

During the week of action, 904 of these "cuckooed" homes were visited by law enforcement, and 1,138 vulnerable people were safeguarded, including 573 children.

From BBC ● May 26, 2021

When William Butler Yeats paid his first visit to that high priestess of occultism, Madame Blavatsky, the lady's pet cuckoo came out of a broken Swiss clock and cuckooed at him.

From Time Magazine Archive

The cuckoo-clock in the corner by the stove cuckooed twelve times, and then from without sounded the deep, full tone of the parish-church clock.

From Jena or Sedan? by Franz Beyerlein

However, figures shared exclusively with the BBC show 1,539 incidents of cuckooing were reported to police in London between May 2025 and April 2026.

From BBC ● Jun. 8, 2026

It had 52 cuckooing referrals last year, compared to 29 in the previous 12 months.

From BBC ● Aug. 7, 2024

Sgt Elise Wilson, who works closely with organisations like Positive Steps, said it was just one way cuckooing can be uncovered.

From BBC ● Aug. 7, 2024

Earlier this month, Northamptonshire Police issued an appeal to tackle the "increasing problem" of cuckooing.

From BBC ● Mar. 27, 2018

I think the way she's taken her place at Cheverley Chase without cuckooing all that family out, or making them jealous, is just marvelous.

From The Princess of the School by Frank Wiles

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