To equivocate is to confuse the meaning of a single term by changing contexts. For example, an equivocation of the term evolution would be as follows: "Evolution states that one species can change into another. We see that cars have evolved into different styles. Therefore, since evolution is a fact in cars, it is true in species." In this example, the first instance of "evolution" deals with the scientific theory. The second deals with engineered designs in cars.
False religious systems often use equivocation to twist Scripture to make it say what they want it to say.