an alarm that alerts security personnel or the police without the knowledge of the intruder or criminal whose presence triggers it: The silent alarm set off a flashing light at the police station.
any visual rather than audible alarm.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use silent alarm in a sentence
And then, some silent alarm clicked into place in Sabo's mind, tightening his stomach, screaming to be heard.Derelict | Alan Edward Nourse
“The silent alarm,” she murmured as she hastily drew from her pocket two dark cylinders.
By the aid of the silent alarm she had received a message from her.
Until now the silent alarm had been little more than a plaything.
Maybe that's why I didn't show up any better, here the other night, when Vee rings in this silent alarm on me.The House of Torchy | Sewell Ford