noun
: the final stage of alert in which attack by enemy aircraft appears to be imminent ; also : the signal for this
at the sound of the red alert pedestrians must take shelter
— compare blue alert , white alert , yellow alert
noun
: the final stage of alert in which attack by enemy aircraft appears to be imminent ; also : the signal for this
at the sound of the red alert pedestrians must take shelter
— compare blue alert , white alert , yellow alert
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012