|Equivocation is the misleading use of a term with more than one meaning by glossing over which meaning is intended at any particular time. As a logical fallacy it is the use of a term more than once in a syllogism but giving the term a different meaning each time and as such it is a type of the fallacy of four terms.
Equivocation is often confused with amphiboly. However, equivocation is ambiguity arising from the misleading use of a word and amphiboly is ambiguity arising from the misleading use of punctuation or syntax.
Puns are a form of word-play and a type of equivocation that relies upon two different words that sound alike. Puns are not a fallacy because the ambiguity is only intended to be momentarily misleading and is in fact the point of the exercise.
Example 1, of equivocation:
The argument is fallacious because the word “light” is first used as the opposite of “heavy” but then used as a synonym of “bright” and so it is actually an example of the fallacy of four terms.
This is an example of equivocation and therefore misleads the audience because the word “country” is used in two different senses. In its first occurrence
Wikipedia claims that this is an example of amphiboly but it is at least as equally an example of equivocation because it conforms to the above definition of equivocation: the first occurrence of “nothing” is equivalent to “the absence of anything” and the second is equivalent to “no other thing.” It becomes clear that these two meanings are distinct from one another, and therefore an equivocation, by swapping them and confirming that the premises do not remain the same.
A clearer example of amphiboly, that is not equivocation, is the following sentence. Notice that it needs extra punctuation and it takes on different meanings according to the number and positions of the commas and quotation marks that one inserts:
Note on the picture:
The picture is an illustration of the example of the ham sandwich given in episode 16, which was given in that episode to mark the distinction between the fallacy of four terms and equivocation. So review that example if you find the picture unclear. It was just too good to pass up as an illustration for the current episode.