A deleted tweet that is still alive due to being caught in a retweet
@flayman RT: @davidallengreen: Dear god... RT @racco: is there no “Sky” High Court to take it to? < good one :-/
in this example. @davidallengreen's original tweet (itself a retweet with a comment) is no longer alive due to him deleting it. But it still lives on because it was caught in @flayman's retweet of said tweet.
So even though the tweets creator deleted it. it's not dead. its now a Zombie Tweet