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; humming. Humming-bird (1630s) so called from sound made by the rapid vibration of its wings.
There is a curious bird to see to, called a humming bird, no bigger then a great Beetle. [Thomas Morton, "New English Canaan," 1637]
hum (n.)
mid-15c., from hum (v.).
实用例句
1. Hum, I am sorry but I thought you were French.
嗯，很抱歉，我以为你是法国人。
来自柯林斯例句
2. There was a general hum of conversation around them.
他们周围的人都在嗡嗡地低声交谈。
来自柯林斯例句
3. My general reaction to this news might be summed up as "ho-hum"
