Someone who has not mastered the very simple difference between email's "reply" and "reply all" actions. The RE-tard is consistently spamming a distribution list's mailbox with their comment, which is relevant only to them and the sender. A true RE-tard will do this even when the original sender of an email to many people list explicitly requests recipients do not "reply all."
I can't stand it when a new system rolls out at my job. My AVP boss always spams her stupid questions to the whole company like the RE-tard she is.
Retarded person on the internet who spams you with the entire alphabet, either correct or not, ending it with Z.
It can also refer to people who mis-spell almost every word or every other word and add or replace a letter with Z for no apparent reason. Most of these people can be found on common sites like Myspace, Gaiaonline, Youtube, or any other large site that can show local text by the public.
Most are doing it just to annoy you.
Others are just that stupid.
Today, I was going on Myspace to check my messages when I found the most ridiculous Z-tard that I almost commited genocide.