- hum (v.)
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- late 14c., hommen "make a murmuring sound to cover embarrassment," later hummen "to buzz, drone" (early 15c.), probably of imitative origin. Sense of "sing with closed lips" is first attested late 15c.; that of "be busy and active" is 1884, perhaps on analogy of a beehive. Related: Hummed.
- hum (n.)
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- mid-15c., "a murmuring sound made with the voice," from hum (v.).