Since you asked, Defame means:
To charge falsely or with malicious intent; attack the good name and reputation of someone; "The journalists have defamed me!" "The article in the paper sullied my reputation
...or in English and American law, and systems based on them, libel and slander are two forms of defamation (or defamation of character), which is the tort or delict of making a false statement of fact that injures someone's reputation. "Defamation" is however the generally-used term internationally, and is accordingly used in this article where it is not necessary to distinguish between "libel" and "slander".
In DoD, defaming is a shooting offence, however since we all shoot everyone as a matter of normal business, it is cheerfully tolerated within reason.
...and BTW, since you were able to post, you know that Noyade was only kidding about locking the thread, right?