Doublespeak

Doublespeak is language that deliberately disguises, distorts, or reverses the meaning of words. Doublespeak may take the form of euphemisms (e.g., “downsizing” for layoffs), making the truth less unpleasant, without denying its nature. It may also be deployed as intentional ambiguity, or reversal of meaning (for example, naming a state of war “peace”). In such cases, doublespeak
disguises the nature of the truth, producing a communication bypass.

The term doublespeak was coined in the 1950s. Inspired by George Orwell’s 1949 dystopian novel Nineteen Eighty-Four, after the fashion of “doublethink.” The model word is described in the novel:

“Winston sank his arms to his sides and slowly refilled his lungs with air. His mind slid away into the labyrinthine world of doublethink. To know and not to know, to be conscious of complete truthfulness while telling carefully constructed lies, to hold simultaneously two opinions which cancelled out, knowing them to be contradictory and believing in both of them…”
– George Orwell, 1984

Doublespeak (from wikipedia.org)

Example: Jobless Claims Rise, but Trend Shows Improvement
Yahoo News, 12-02-10