coo

¹ American  

[koo] / ku /

verb (used without object)

cooed, cooing

1. to utter or imitate the soft, murmuring sound characteristic of doves.

2. to murmur or talk fondly or amorously.

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verb (used with object)

cooed, cooing

1. to utter by cooing.

noun

1. a cooing sound.

coo ² American  

[koo] / ku /

interjection

British Slang.

1. (used to express surprise or amazement.)

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Coo ³ American  

[kaw-aw] / ˈkɔ ɔ /

noun

1. Italian name of Kos.

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COO ⁴ American  

1. chief operating officer.

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coo ¹ British  

/ kuː /

verb

1. (intr) (of doves, pigeons, etc) to make a characteristic soft throaty call

2. (tr) to speak in a soft murmur

3. (intr) to murmur lovingly (esp in the phrase bill and coo )

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noun

1. the sound of cooing

interjection

1. slang an exclamation of surprise, awe, etc

CoO ² British  

abbreviation

1. cost of ownership

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COO ³ British  

abbreviation

1. chief operating officer

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Other Word Forms

• cooer noun
• cooingly adverb

Etymology

Origin of coo¹

First recorded in 1660–70; imitative

Origin of coo²

First recorded in 1910–15; origin uncertain

Explanation

A coo is the low, sweet sound that a bird makes, especially a dove or pigeon. If a dove builds a nest outside your open window, you'll be able to hear its coos every morning. There is a small, gray pigeon that's called a mourning dove because its coo is so sad sounding. When you hear a bird making this distinctive sound, you can also say that it coos — and if a person murmurs in a low, soft voice, you can say that she coos too. The word coo has been used since at least the late 1600s, and its origin is probably imitative, the word sounding very much like the sound it describes.

Example Sentences

McCain also tried to extract sentimental details about the passionate romance between the Vances, for her audience to coo over.

From Salon • Aug. 11, 2025

After birth, a baby is immediately immersed in a sea of words and rhythm, as their caregivers coo over them, chatter and sing lullabies.

From Los Angeles Times • Jun. 24, 2025

If at all possible, you should live in a place where you don't have to constantly be looking over your shoulder in fear while you coo at the baby.

From Science Daily • Mar. 18, 2024

They coo and fuss over the infant, swap feeding and nappy-changing duties, and take turns to stay with him so one of them can get some sleep.

From BBC • Oct. 2, 2023

"Can we peek?" one woman asks, and Mina stops so they can coo at the sleeping baby.

From "Girl in the Blue Coat" by Monica Hesse

Related Words

• murmur