Meaning

noun the state of being or appearing to be actively engaged in an activity

noun an Islamic fundamentalist group in Pakistan that fought the Soviet Union in Afghanistan in the 1980s; now operates as a terrorist organization primarily in Kashmir and seeks Kashmir's accession by Pak

noun a humming noise

originFrom Middle English hummen (“to hum, buzz, drone, make a murmuring sound to cover embarrassment”); akin to Dutch hommelen (“to bumble, buzz”), dialectal Dutch hommen (“to buzz, hum”), Middle High German hummen (“to hum”), probably ultimately of imitative origin.

Etymology from Wiktionary, CC BY-SA 3.0