Truthiness
A panel of linguists, the American Dialect Society, has looked over the possible candidates and decided that "truthiness" is the word that best describes the old year of 2005. They define truthiness as the quality of stating concepts one wishes or believes to be true. True as opposed to factual. One of the linguists, Michael Adams of North Carolina State explains:"The national argument right now is, one, who's got the truth and, two, who's got the facts. Until we can manage to get the two of them back together again, we're not going to make much progress."
The linguists also decided that "podcast" was the most useful new word, and "whale tail" (which wasn't used, but figured prominently in Sunday's West Wing) edged "muffin top" (gross!) in a runoff for most creative word.