• noun:   a humming noise

  Example: "The hum of distant traffic"

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

  Example: "There is a constant hum of military preparation"

• verb:   sound with a monotonous hum
• verb:   be noisy with activity
• verb:   sing with closed lips

  Example: "She hummed a melody"

• verb:   make a low continuous sound

  Example: "The refrigerator is humming"

• name:  A surname (very rare: popularity rank in the U.S.: #56600)

Related words...