When an unclear phrase with multiple definitions is used within the argument; therefore, does not support the conclusion. Some will say single words count for the ambiguity fallacy, which is really a specific form of a fallacy known as equivocation .
Examples:
- It is said that we have a good understanding of our universe. Therefore, we know exactly how it began and exactly when.
Synonyms: ambiguous assertion, amphiboly, amphibology, semantical ambiguity, vagueness