Makes soft murmuring sounds like a dove or pigeon; or speaks in soft, gentle tones.
From Old English 'cu' or imitative origins (onomatopoeia). The sound 'coo' directly mimics the call of doves and pigeons. The term also metaphorically means speaking softly and affectionately.
Baby birds coo to their parents for food, and incredibly, pigeons and doves produce a special 'crop milk' from their throats to feed chicks—completely different from mammals!
Often gendered feminine (baby talk, soft/diminishing speech attributed to women); historically used to mock or infantilize women's voices.
Use descriptively for sound without gendered assumption. 'They coo' is neutral; avoid implying the sound or speaker is inherently feminine.
["murmurs","soft vocalizations","gentle sounds"]
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