buzzer

Từ điển Oxford Advanced Learner 8th

buzz·er [buzzer buzzers] BrE [ˈbʌzə(r)] NAmE [ˈbʌzər] noun
an electrical device that produces a ↑buzzing sound as a signal
•Put your fingers on the buzzer and be ready to answer.
Idiom: ↑at the buzzer

Example Bank:
•The buzzer went off at eight o'clock.

• Từ đồng nghĩa / Synonyms:
  doorbell, bell