Glossary
Compliance as code
Compliance as code is the practice of expressing and checking compliance obligations where the system actually lives, in the repository and the pipeline, rather than only in a policy document reviewed once a year. It borrows the move that worked for testing and infrastructure: take something manual and periodic and make it defined and continuous.
In code
In practice it means a control is named at a grain you can check ('a privileged role change must be logged'), the check runs on the pull request where changes happen, and a finding cites the specific control so an engineer can act on it.