alarm clock

US /əˈlɑːrm klɑːk/
UK /əˈlɑːrm klɑːk/
"alarm clock" picture
1.

despertador

a clock that can be set to wake a person at a particular time by sounding a buzzer or bell

:
I set my alarm clock for 6 AM.
Eu ajustei meu despertador para as 6 da manhã.
The loud ringing of the alarm clock startled me awake.
O toque alto do despertador me assustou e me acordou.