A weasel word, or anonymous authority, is an informal term for words and phrases such as "researchers believe" and "most people think" which make arguments appear specific or meaningful, even though these terms are at best ambiguous and vague. Using weasel words may allow someone to later deny any specific meaning if the statement is challenged, because the statement was never specific in the first place. Weasel words can be a form of tergiversation, and may be used in advertising and political statements to mislead.
Weasel words can soften or under-state a biased or otherwise controversial statement. An example of this is using terms like "somewhat" or "in most respects," which make a sentence more ambiguous than it would be without them.
The expression weasel word may derive from the egg-eating habits of weasels. An article published by the Buffalo News attributes the origin of the term to William Shakespeare's plays Henry V and As You Like It, in which the author includes similes of weasels sucking eggs. The article said that this was a misnomer, because weasels do not have a mandible suitable for sucking eggs.
Ovid's Metamorphoses provides an earlier source for the same etymology. Ovid describes how Juno orders the goddess of childbirth, Lucina, to prevent Alcmene from giving birth to Hercules. Alcmene's servant Galanthis, realizing that Lucina is outside the room using magic to prevent the birth, emerges to announce that the birth has been a success. Lucina, in her amazement, drops the spells of binding and Hercules is born. Galanthis then mocks Lucina, who responds by transforming her into a weasel. Ovid writes (in A.S. Kline's translation) "And because her lying mouth helped in childbirth, she [as a weasel] gives birth through her mouth."
Definitions of the word 'weasel' that imply deception and irresponsibility include: the noun form, referring to a sneaky, untrustworthy, or insincere person; the verb form, meaning to manipulate shiftily; and the phrase "to weasel out", meaning "to squeeze one's way out of something" or "to evade responsibility".
The expression first appeared in Stewart Chaplin's short story "Stained Glass Political Platform" (published in 1900 in The Century Magazine), in which weasel words were described as "words that suck the life out of the words next to them, just as a weasel sucks the egg and leaves the shell". Theodore Roosevelt attributed the term to his friend William Sewall's older brother, Dave, claiming that he used the term in a private conversation in 1879. In another early usage, Theodore Roosevelt argued in 1916 that "one of our defects as a nation is a tendency to use ...'weasel words'; when one 'weasel word' is used ... after another there is nothing left".
Other forms of weasel words may include these:
Generalizing by means of quantifiers, such as many, when quantifiable measures could be provided, obfuscates the point being made, and if done deliberately is an example of "weaseling".
Non sequitur, where illogical or irrelevant statements can be used, such as in advertising, can make it appear that the statement describes a beneficial feature of a product or service being advertised. An example is the endorsement of products by celebrities, regardless of whether they have any expertise relating to the product. In non sequitur fashion, it does not follow that the endorsement provides any guarantee of quality or suitability.
False authority is defined as the use of the passive voice without specifying an actor or agent. For example, saying "it has been decided" without stating by whom, and citation of unidentified "authorities" or "experts", provide further scope for weaseling. It can be used in combination with the reverse approach of discrediting a contrary viewpoint by glossing it as "claimed" or "alleged". This embraces what is termed a "semantic cop-out", represented by the term allegedly. This implies an absence of ownership of opinion, which casts a limited doubt on the opinion being articulated. The construction "mistakes were made" enables the speaker to acknowledge error without identifying those responsible.
However, the passive voice is legitimately used when the identity of the actor or agent is irrelevant. For example, in the sentence "one hundred votes are required to pass the bill", there is no ambiguity, and the actors including the members of the voting community cannot practicably be named even if it were useful to do so.
The scientific journal article is another example of the legitimate use of the passive voice. For an experimental result to be useful, anyone who runs the experiment should get the same result. That is, the identity of the experimenter should be of low importance. Use of the passive voice focuses attention upon the actions, and not upon the actor--the author of the article. To achieve conciseness and clarity, however, most scientific journals encourage authors to use the active voice where appropriate, identifying themselves as "we" or even "I".
The middle voice can be used to create a misleading impression. For example:
The first of these also demonstrates false authority, in that anyone who disagrees incurs the suspicion of being unreasonable merely by dissenting. Another example from international politics is use of the phrase "the international community" to imply a false unanimity.
Euphemism may be used to soften and potentially mislead the audience. For example, the dismissal of employees may be referred to as "rightsizing", "headcount reduction", and "downsizing".Jargon of this kind is used to describe things euphemistically.
Restricting information available to the audience is a technique sometimes used in advertisements. For example, stating that a product "... is now 20% cheaper!" raises the question, "Cheaper than what?". It might be said that "Four out of five people prefer ..." something, but this raises the questions of the size and selection of the sample, and the size of the majority. "Four out of five" could actually mean that there had been 8% for, 2% against, and 90% indifferent.
Weasel words can also be used to try to weaken factual statements, for example "The ruling was met with criticism by human rights organizations such as Amnesty International and Human Rights Watch" can be amended to read "The ruling was met with criticism by some human rights organizations such as..."
suggests that today's 18-year-olds are too immature to vote. We should be talking about raising the voting age, not lowering it...
In Report on Unidentified Flying Objects (1956), US Air Force Captain Edward J. Ruppelt described astronomer Dr. J. Allen Hynek's report on the death of pilot Thomas Mantell in pursuit of a UFO as "a masterpiece in the art of 'weasel wording'."
Carl Wrighter discussed weasel words in his best-selling book I Can Sell You Anything (1972).
Australian author Don Watson devoted two volumes (Death Sentence and Watson's Dictionary of Weasel Words) to documenting the increasing use of weasel words in government and corporate language. He maintains a website encouraging people to identify and nominate examples of weasel words.
Scott Adams, the creator of the Dilbert comic strip, talks much about 'weasels' as being conniving businesspeople in one of his books, named accordingly: Dilbert and the Way of the Weasel (2002).