Wind-down

The period in which a warning siren's pitch lowers as the motor is no longer energized.

The siren is currently winding down.
The siren's wind-down took a while.

smoke detector

A device, typically used within Fire Safety, to warn of smoke.

Smoke detectors are required in all levels of a house, including basements and locations where someone may sleep.

Penis

Male genital.

Dude, have you seen his penis???

Gun

A weapon that discharges a ballistic round.

Want to shoot a gun?

Siren

A device that outputs a loud sound to warn of danger.

The siren is sounding.

Tornado

A rotating column of air with winds excessive of 42 miles per hour+, often extending from a thunderstorm cloud.

I have spotted a tornado on the ground.