• (British) IPA: /ˈbʌzə/
• (America) IPA: /ˈbʌzəɹ/

buzzer (plural buzzers)

1. One who, or that which, buzzes; an insect that buzzes.
   • c. 1599–1602, William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act IV, scene v]:

     And wants not buzzers to infect his ear / With pestilent speeches of his father's death.

2. A device that makes a buzzing sound.

   If you think you know the answer to the question, hit the buzzer as fast as you can.

3. (US slang) A police badge.
   • 1939, Raymond Chandler, The Big Sleep, Penguin 2011, p. 28:

     I flipped my wallet open on her desk and let her look at the buzzer pinned to the flap.

4. (cricket, slang) A run scored from an overthrow.
5. (obsolete) A gossip.
   • c. 1599–1602, William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act IV, scene v]:

     Her brother is in secret come from France,
     Feeds on this wonder, keeps himself in clouds
     And wants not buzzers to infect his ear
     With pestilent speeches of his father's death.

• French: bipeur
• German: Summer, Buzzer
• Italian: segnalatore acustico, cicalino
• Portuguese: cigarra
• Russian: зу́ммер
• Spanish: bocina, zumbador