Examples of using "будильника" in a sentence and their english translations:
She overslept.
We overslept.
I wake up at the sound of the alarm.
Didn't you hear the alarm clock?
Tom woke up a few minutes before the alarm.
Didn't you hear the alarm clock?
The alarm didn't wake Tom.
It's much better to be woken by the birds than by an alarm.
Tom always sets two alarm clocks when he's catching the early morning flight.
If you find it hard to wake up in the morning, then set your ringtone as your alarm. Then it will seem to you that you are being called.