Что (кто) такое zombie process - определение

On Unix and Unix-like computer operating systems, a zombie process or defunct process is a process that has completed execution (via the exit system call) but still has an entry in the process table: it is a process in the "Terminated state". This occurs for the child processes, where the entry is still needed to allow the parent process to read its child's exit status: once the exit status is read via the wait system call, the zombie's entry is removed from the process table and it is said to be "reaped".

<operating system> (Or "defunct process") A Unix process that has terminated (either because it has been killed by a signal or because it has called exit()) and whose {parent process} has not yet received notification of its termination by executing (some form of) the wait() system call. A zombie process exists solely as a process table entry and consumes no other resources. This entry is retained to hold the child's exit status until the parent process wants to retrieve it. The parent can also be notified asynchronously via a signal of the child's termination. Zombie processes can be seen in "ps" listings occasionally (with a status "Z" in some versions). Compare orphan process. (1997-10-08)

In computing, a zombie is a computer connected to the Internet that has been compromised by a hacker via a computer virus, computer worm, or trojan horse program and can be used to perform malicious tasks under the remote direction of the hacker. Zombie computers often coordinate together in a botnet controlled by the hacker, and are used for activities such as spreading e-mail spam and launching distributed denial-of-service attacks (DDoS attacks) against web servers.