A zombie is:

1. A rum drink:

• 2 1/2 oz Light rum
• 1 oz Jamaica rum
• 1/2 oz Apricot flavored brandy
• 1 oz unsweetened pineapple juice
• 1 oz passion fruit syrup
• juice of 1 lime
• juice of one orange
• 1 tsp powdered sugar
• 1/2 oz 151-proof rum

2. An Undead creature that feeds on the brains of the living.

3. On a Unix system, a Process that has called exit(3), but whose parent process has not yet called the wait() function to be notified of its termination.

Note that although zombie processes will show up in ps(1) and top(1), the only resource they use is an entry in the process table; they cannot be allocated memory or CPU time.

The only way to get rid of a zombie process is to either kill the parent process, or convince it to call wait().

Pressing the i key in top will tell it not to display idle and zombie processes.

Want to know more? Have a look at ZombieProcess or the manpages for ps(1), top(1) and wait(2).