pan·ic 
(pănĭk)
(pănĭk)n.
1. A sudden, overpowering feeling of fear, often affecting many people at once. See Synonyms at fear.
2. A state of extreme anxiety, such as that involved in a panic attack.
3.
a. A state of frantic activity, usually accompanied by extreme concern or anxiety: The office was in a panic as the deadline approached.
b. A sudden widespread alarm concerning finances, often resulting in a rush to sell property to raise cash.
4. Slang A person or thing that is considered extremely funny.
adj.
1. Of, relating to, or resulting from sudden, overwhelming terror: panic flight.
2. Of or resulting from a financial panic: panic selling of securities.
3. often Panic Mythology Of or relating to Pan.
tr. & intr.v. pan·icked, pan·ick·ing, pan·ics
To affect or be affected with panic. See Synonyms at frighten.
[From French panique, terrified, from Greek Pānikos, of Pan (a source of terror, as in flocks or herds), groundless (used of fear), from Pān, Pan; see PAN.]
panick·y adj.