regex

This term is a clipped form of regular expression, widely used in technical documentation, programming forums, and developer conversations. While "regular expression" is the formal term, "regex" is the standard shorthand in professional software engineering contexts.

Because it is a technical term, it is typically used as a countable noun. Developers often refer to "a regex" when discussing a specific pattern or "regexes" when referring to multiple patterns used across a codebase.