fire alarm 
noun
A device making a loud noise that gives warning of a fire: a fire alarm went off and the building had to be evacuated...
- This time the ringing noise wasn't the fire alarm, but the dinner bell.
- That was when the idiots decided to test the fire alarm without the usual warning over the speakers.
- One girl bolted to the fire alarm and pulled it, setting the siren wailing and then sprinting for the door.
- digital rights management
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- digital subscriber loop
- digital television
- digital-to-analog
- digital-to-analogue
- digital-to-analogue converter
- digital tuner
- digital tuning
- digital TV
- digital video disc
- digital video disk
- digital video recorder
- digital watermark
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- digitary
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- digitation
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- digitiform
- digitigrade
- digitigradism
- digitin