1) Disproof 2) Falsification 3) Mathematical terminology 4) Refutation 5) Refutation by example 
In logic, and especially in its applications to mathematics and philosophy, a counterexample is an exception to a proposed general rule or law. For example, consider the proposition `all students are lazy`. Because this statement makes the claim that a certain property (laziness) holds for all students, even a single example of a diligent studen.....
[n] - refutation by example
noun refutation by example
an example that refutes an assertion or claim.