audible warning

audible alarm

audible tone

audible knock

Warning text that appears when the battery voltage falls below warning threshold

advance warning

advance-warning satellite

air defense early warning

airborne early warning (AEW)

airborne early warning aircraft

airborne warning and control aircraft

Airborne Warning and Control System (AWACS)

distant early warning line

early warning (air defense)

early warning (EW)

early warning ground-based radar (EW GBR)

early warning radar station

early warning sharing (system) (EWS)

early warning system (EWS)

early warning system (EWS) operator

fire a warning shot

gas alarm / warning

missile attack warning

missile early-warning system

missile warning

Movement Warning Order (MWO)

NATO Airborne Early Warning and Control Force

NATO Intelligence Warning System (NIWS)

phased array warning system (PAWS)

public warning

radar warning

radar warning equipment

radar warning receiver (RWR)