Panic

1. Extreme or sudden and causeless; unreasonable; -- said of fear or fright; as, panic fear, terror, alarm.
2. A sudden, overpowering fright; esp., a sudden and groundless fright; terror inspired by a trifling cause or a misapprehension of danger; as, the troops were seized with a panic; they fled in a panic.
3. By extension: A sudden widespread fright or apprehension concerning financial affairs.
4. A plant of the genus Panicum; panic grass; also, the edible grain of some species of panic grass.