1. <operating system> 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.