Which term is used to describe the process of ensuring that high-level programming language code is clear and understandable?

The term that effectively describes the process of ensuring that high-level programming language code is clear and understandable is "readability." Readability pertains to how easily a human can read and comprehend the code. It encompasses the clarity of the code's structure, use of meaningful variable names, consistent formatting, and appropriate comments that elucidate the purpose and function of different sections of code.

Readable code enables other programmers (or even the original author at a later time) to understand the logic and flow of the code swiftly, facilitating easier maintenance and reducing the likelihood of errors. High readability is pivotal for collaborative working environments, where multiple developers might interact with the same codebase.

While documentation refers to the written descriptions accompanying the code that explain how to use it, readme files, or specific functions and modules, it is more about providing supporting information rather than the inherent clarity of the code itself. Debugging involves finding and fixing errors in the code, and refactoring is the process of restructuring existing code without changing its external behavior to improve its readability or reduce complexity. Both debugging and refactoring can enhance readability but are not solely focused on informing how clear the code is from the outset.