The Dilbert Blog: Weasel Nominees for 2006:
"By way of definition, a weasel is someone who is trying to get away with something and actually succeeding. We don’t include anyone who is in jail because that person isn’t getting away with it.
We also don’t include anyone who is evil or annoying or incompetent but in an honest way. A weasel is someone who craps on toast and tells you it is caviar. Weasels say things like this:
“I have never taken steroids. I look like the Incredible Hulk because I eat right.”
“I didn’t realize I was stealing a billion dollars from my company. I just signed whatever they put in front of me.”
“I deserve my $100 million salary because without me the company’s stock price would have plunged even further.”"