humming

Etymology 1

From hum + -ing.

verb

1. present participle and gerund of hum

adj

1. Making a hum sound.
2. (archaic) Of ale or beer: very strong.
   But at night crowds of visitors called at his cot, / For he told a right marvellous tale; / Yet a stronger attraction by chance he had got, / A barrel of old humming ale. 1889, John Bickerdyke, The Curiosities of Ale & Beer: An Entertaining History, page 13

Etymology 2

From Middle English hummynge, equivalent to hum + -ing.

noun

1. The sound of something that hums; a hum.
   There are some contemporary additions to these scattered fragments from Shakespeare. Mostly they are songs; sometimes they are various screechings and hummings[…] 8 December 1969, New York Magazine, volume 2, number 49, page 70