Weasel words is an informal term for words and phrases aimed at creating an impression that something specific and meaningful has been said, when in fact only a vague or ambiguous claim has been communicated. For example, an advertisement may use a weasel phrase such as "up to 50% off on all products"; this is misleading because the audience is invited to imagine many items reduced by the proclaimed 50%, but the words taken literally mean only that no discount will exceed 50%, and in practice the vendor is free to not reduce any prices and still remain faithful to the wording of the advertisement.
The use of weasel words to avoid making an outright assertion is a synonym to tergiversate. Weasel words can imply meaning far beyond the claim actually being made. Some weasel words may also have the effect of softening the force of a potentially loaded or otherwise controversial statement through some form of understatement, for example using detensifiers such as "somewhat" or "in most respects".
to tergiversate (third-person singular simple present tergiversates, present participle tergiversating, simple past and past participle tergiversated)
1. (intransitive) To evade, to equivocate using subterfuge; to deliberately obfuscate.
2. (intransitive) To change sides or affiliation; to apostatize.
From Wikipedia the free encyclopaedia [edited for clarity]