A ZombieUrl is an "unbroken" link such as http://thephpwtf.com/. It is now a BrokenLink, with no server, While in the past it may have had a server, it did not provide useful content by any stretch of the imagination.
Very good for clogging up Ask.com searches, which is why I normally use Google. --AnonymousDonor
Related to the VultureSearchEngine, in that both take over formerly useful URLs for evil purposes.