What does coo mean?
Coo is both a verb and, less commonly, a noun referring to the soft, low, murmuring sound characteristic of doves and pigeons. As a verb, it describes either an animal producing that sound or a person speaking in a gentle, tender, affectionate manner — parents famously coo over babies, and lovers may coo endearments at each other. The word is imitative in origin, coined simply to mimic the bird's call, and has been part of English since at least the early modern period. In everyday usage it carries warm, sentimental associations, though it can be used teasingly when someone is seen as excessively doting or syrupy in tone. Beyond its literal sense, coo appears frequently in descriptions of pastoral scenes and in writing about early childhood, where the term 'cooing' also names an early stage of infant vocalization before babbling. Its simplicity and evocativeness make it a quietly useful word for expressing gentleness.
To make a soft, low murmuring sound like that of a dove; to speak gently and affectionately.
"She cooed softly to the infant until he drifted off to sleep."
The soft, low murmuring cry of a dove or pigeon.
"The quiet coo of the mourning dove filled the garden at dawn."
The plural applies only to the noun sense (the sound itself); multiple instances are usually described collectively rather than counted.
"The doves' soft coos echoed through the courtyard all morning."
When pigeons coo outside your window, they're making the very sound that gave us one of English's oldest onomatopoeic words — and it has nothing to do with a military coup.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of coo
The word 'coo' is onomatopoeic in origin — it was formed by imitating the actual murmuring sound made by doves and pigeons rather than descending from any earlier classical root. It appears in English from around the mid-17th century, first recorded in writings describing birdsong, and later extended metaphorically to describe soft, loving human speech. Related imitative formations include 'cuckoo', which mimics a different but similarly distinctive bird call.
Related word forms
How coo is actually used
As a verb describing human speech, 'coo' carries warm, sentimental connotations — often used of lovers, parents with babies, or anyone speaking with exaggerated tenderness. It can occasionally carry a slightly mocking tone when describing someone being overly sweet or fussy. The bird sense is purely descriptive and neutral.
Easily confused with coo
A 'coup' is a sudden, decisive act of political or strategic seizure (from French), while 'coo' is the gentle sound made by doves or by people speaking tenderly.