hum

B1 · Intermediate

v. to make a continuous low sound like a machine or a bee.

v. to produce a continuous low-frequency sound, characteristic of insects in flight or electrical machinery.

“The refrigerator hums quite loudly during the night.”

“The server room hummed with the constant vibration of cooling fans and high-speed processors.”

B2 · Upper Intermediate Informal

v. to be full of activity and energy.

v. to be in a state of intense, productive activity or excitement.

“By ten o'clock, the office was really humming with activity.”

“The factory floor was humming as the team worked overtime to meet the end-of-quarter production targets.”

C1 · Advanced British English · Slang · Informal

v. to have a very strong and unpleasant smell.

v. to emit a powerful and offensive odour. Intransitive use.

“Those old gym shoes are starting to hum.”

“After a week without a working fridge, the entire kitchen began to hum with the scent of spoiled milk.”

B1 · Intermediate Countable noun

n. a low, steady, continuous sound.

n. a continuous low-pitched sound, such as that made by a motor or a distant crowd.

“There was a constant hum of traffic from the nearby highway.”

“The quiet hum of the air conditioning was the only sound in the deserted library.”