humming Meaning, Definition & Usage

1. noun a humming noise
   hum.
   
   • the hum of distant traffic
2. noun the act of singing with closed lips
   
3. verb sing with closed lips
   hum.
   
   • She hummed a melody
4. verb be noisy with activity
   hum; seethe; buzz.
   
   • This office is buzzing with activity
5. verb sound with a monotonous hum
   hum; thrum.
   
6. verb make a low continuous sound
   hum.
   
   • The refrigerator is humming

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