Also known as Double-Speak (see 1984 by George Orwell). This fallacy falls under the "Fallacies of Ambiguity" category because it is the ambiguous usage of wording. 

This has nothing to do with grammar or punctuation but, rather, how a word or phrase is defined by one arguer as opposed to how it is defined by the other arguer OR when an arguer uses a word or phrase to mean one thing in one portion of their argument and then something different in another part of their argument. 

To avoid this fallacy's use in formal debate, the first task is for definitions of important terms to be clarified for both parties and agreed upon.

Example: 

Former U.S. President Bill Clinton famously dodged a question about his behavior while in office by responding:

"That depends on what your definition of is is..."