Definition of "racy"

These are some common descriptions of badly constructed tests: Tests that sometimes run, sometimes fail (often this is caused by the use of threads, or racy code that relies on specific timing, by reliance on external dependencies, the order of tests being run in the test suite, or on shared state)

2014, Pete Goodliffe, Becoming a Better Programmer: A Handbook for People Who Care About Code

We evaluate the automatic fence insertion procedure by running our tool on a number of different benchmarks containing racy code.

2016, Elvira Albert, Ivan Lanese, Formal Techniques for Distributed Objects, Components, and Systems