The ability of a program to examine its own structure, such as variable types and object properties, typically in a read-only manner at runtime.
From Latin 'introspicere' meaning to look within. Psychology adopted it for self-examination of thoughts, and computing borrowed it in the 1980s for programs examining their own structure, typically as a subset of reflection capabilities.
Think of it as a program's ability to be self-aware - like looking in a mirror to see what you're wearing, but for code to see what types and methods it has. Python's dir() function is like asking an object 'what can you do?' and getting a list back!
Complete word intelligence in one call. Free tier — 50 lookups/day.