alarm clock
US /əˈlɑːrm klɑːk/
UK /əˈlɑːrm klɑːk/

1.
闹钟
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.
我把闹钟定在早上6点。
•
The loud ringing of the alarm clock startled me awake.
闹钟响亮的铃声把我吓醒了。