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

---

adjective

1. informal insane or foolish

interjection

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

verb

1. (tr) to repeat over and over

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

cuckoo Idioms  

1. see cloud-cuckoo land.

---

Other Word Forms

Noun Inflected Forms

• cuckoos
  plural

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.

Example Sentences

See Examples For:

cuckoo cuckoos cuckooed cuckooing

Soccer is just as cuckoo as any of our usual sports.

From The Wall Street Journal ● Jul. 20, 2026

And that has momentum traders going cuckoo for qubits.

From Barron's ● May 29, 2026

The estate is home to rare wildlife, including curlew, mountain bumblebees, lapwings, red squirrels, cuckoo and merlin, as well as Atlantic salmon and critically endangered eels, but the conservationists say nature could be richer still.

From BBC ● Oct. 29, 2025

“The cuckoo clock, the Dutch door, the daylight basement — humble horsemen of the domestic Apocalypse. The VWs, parked in the driveway.”

From Los Angeles Times ● Jun. 5, 2025

Vivian was a normal, sensible person, but I think at that time she must have gone a little cuckoo.

From "Milkweed" by Jerry Spinelli

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

I snap the book shut and as if on cue, several cuckoos appear from intricately carved wooden clocks, announcing the hour half past.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

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 second song seems to me as irrelevant as the first," said Joscelyn, "but I observe that you cuckooed so loudly as to startle our mistress out of her inattention.

From Martin Pippin in the Apple Orchard by Eleanor Farjeon

Ahead of the implementation of the law change, the BBC accompanied London's Metropolitan Police as officers visited suspected cuckooing properties and witnessed shocking signs of squalor.

From BBC ● Jun. 8, 2026

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

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

Positive Steps was recently awarded £344,000 to expand its cuckooing service, which had previously only been operating with one dedicated staff member, Gillian Anderson.

From BBC ● Aug. 7, 2024

Miss Poppy eyed him as if he were a cuckoo-clock, and she had to wait till he'd finished cuckooing.

From The Lost Girl by D. H. (David Herbert) Lawrence