[1] : WordNet (r) 2.0

warning signal
     n : an automatic signal usually a sound warning of danger
         syn: alarm, alert, alarum
see also:
alarm alert alarum 

Signal >> S Words
Signal, definition of term: Signal
signal_pag1.html

Warning >> W Words
Warning, definition of term: Warning
warning_pag1.html

Warning Device >> W Words
Warning Device, definition of term: Warning Device
warning+device_pag1.html

Signal Light >> S Words
Signal Light, definition of term: Signal Light
signal+light_pag1.html

Signal Flag >> S Words
Signal Flag, definition of term: Signal Flag
signal+flag_pag1.html

Distress Signal >> D Words
Distress Signal, definition of term: Distress Signal
distress+signal_pag1.html

Digital Signal >> D Words
Digital Signal, definition of term: Digital Signal
digital+signal_pag1.html

Turn Signal >> T Words
Turn Signal, definition of term: Turn Signal
turn+signal_pag1.html

Traffic Signal >> T Words
Traffic Signal, definition of term: Traffic Signal
traffic+signal_pag1.html

Early Warning S >> E Words
Early Warning S, definition of term: Early Warning S
early+warning+s_pag1.html