Confound (verb)

1. To confuse or perplex (someone).
2. To prove (something) to be false or incorrect.

Origin:

From middle english confounden, from latin confundere "to pour together, mix up, confuse".

Examples:

1. The question completely confounded the students.
2. The new evidence confounded the prosecution's case.
3. The sudden change in plans confounded her.
4. The new information confounded the theory.
5. The experiment confounded the scientist's expectations.