panic

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A sudden, overpowering feeling of fear, often affecting many people at once. synonym: fear.
• noun A state of extreme anxiety, such as that involved in a panic attack.
• noun A state of frantic activity, usually accompanied by extreme concern or anxiety.
• noun A sudden widespread alarm concerning finances, often resulting in a rush to sell property to raise cash.
• noun Slang A person or thing that is considered extremely funny.
• adjective Of, relating to, or resulting from sudden, overwhelming terror.
• adjective Of or resulting from a financial panic.
• adjective Mythology Of or relating to Pan.
• transitive & intransitive verb To affect or be affected with panic. synonym: frighten.

from The Century Dictionary.

• noun A grass of the genus Panicum.
• [capitalized] Of or pertaining to the god Pan: as, Bacchic and Panic figures.
• Inspired or as if inspired by Pan: applied to extreme or sudden fright: as, panic fear.
• noun A sudden fright, particularly a sudden and exaggerated fright affecting a number of persons at once; terror without visible or appreciable cause, or inspired by a trifling cause or by misapprehension of danger.
• noun Specifically An exaggerated alarm which takes possession of a trading community on the occurrence of a financial crisis, such as may be caused by the failure of an important bank, or the exposure of a great commercial swindle, inducing a general feeling of distrust, and impelling to hasty and violent measures to secure immunity from possible loss, thus often precipitating a general financial disaster which was at first only feared.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Bot.) A plant of the genus Panicum; panic grass; also, the edible grain of some species of panic grass.
• noun (Bot.) any grass of the genus Panicum.
• adjective Extreme or sudden and causeless; unreasonable; -- said of fear or fright.
• noun A sudden, overpowering fright; esp., a sudden and groundless fright; terror inspired by a trifling cause or a misapprehension of danger
• noun By extension: A sudden widespread fright or apprehension concerning financial affairs.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Pertaining to the god Pan.
• adjective Of fear, fright etc: sudden or overwhelming (attributed by the ancient Greeks to the influence of Pan).
• noun Overpowering fright, often affecting groups of people or animals.
• noun finance, economics Rapid reduction in asset prices due to broad efforts to raise cash in anticipation of continuing decline in asset prices.
• verb To feel overwhelming fear.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun sudden mass fear and anxiety over anticipated events
• verb cause sudden fear in or fill with sudden panic
• noun an overwhelming feeling of fear and anxiety
• verb be overcome by a sudden fear