An unintentional misspelling of an online username when first creating it.
A name is what you are referred to as, and maim means to permanently injure or damage. Put them together and you have name maim.
Me: "My UD username was supposed to be Anarch Furry, which is original, but I wasn't careful and ended up with "Amarch Furry", which doesn't really make sense".
Friend: "Ouch. That's a bad case of name maim."