Test failures: false positive or false negative

If my unit test fails, but the underlying code actually works, would this be called a false positive, or a false negative?

(Here is the context. I run a bunch of tests in parallel and some tests fail. I run them sequentially and they all pass. All the code actually works, there is just an issue with the parallel test runner.)

My question is just with the nomenclature though. I've found examples of people calling it either. After reading Wikipedia, I would've thought it is a false positive, but notably Andrew Ng in his machine learning class said:

If the test passes, even if the code is broken, that is a false positive. If the test fails, when the code is NOT broken, that is a false negative.