A logical fallacy in which the construction of a sentence allows multiple interpretations. If you ever ask an oracle for advice, watch out for this.

Example, using parens to clarify grouping:   Sentence: "I talked about sex with your grandmother."
  Meaning 1: "I talked (about sex) (with your grandmother)."
  Meaning 2: "I talked about (sex with your grandmother)."

To show the Amphiboly, identify the offending phrase and give the two possible interpretations.