1. [n]  an overwhelming feeling of fear and anxiety
2. [n]  sudden mass fear and anxiety over anticipated events; "panic in the stock market"; "a war scare"
3. [v]  cause panic in; fill with panic; "Th mere thought of an isolation cell panicked the prisoners"
4. [v]  feel panic; "The students panicked when told that final exams were less than a week away"

1. \Pan"ic\, n. [L. panicum.] (Bot.)
   A plant of the genus {Panicum}; panic grass; also, the edible
   grain of some species of panic grass.
   
   {Panic grass} (Bot.), any grass of the genus {Panicum}.
   
   

2. \Pan"ic\, a. [Gr. ? of or pertaining to ? Pan, to whom the
   causing of sudden fright was ascribed: cf. F. panique.]
   Extreme or sudden and causeless; unreasonable; -- said of
   fear or fright; as, panic fear, terror, alarm. ``A panic
   fright.'' --Dryden.
   
   

3. \Pan"ic\, n. [Gr. ? (with or without ? fear): cf. F.
   panigue. See {Panic}, a.]
   1. 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.
   
   2. By extension: A sudden widespread fright or apprehension
      concerning financial affairs.
   
   

1. What unix does when a critical internal consistency checks fails in such a way that Unix cannot continue. The kernel attempts to print a short message on the console and write an image of memory into the swap area on disk. This can be analysed later using adb. The kernel will then either wait in a tight loop until the machine is rebooted or will initiate an automatic reboot.

unix manual page: panic(8).

2. Action taken by software which discovers some fatal problem which prevents it from continuing to run.