faulty

This term describes a failure in function or logic, carrying a strong connotation of defectiveness. When applied to physical objects, it suggests a mechanical or electrical breakdown that prevents the item from performing its intended purpose, often implying a manufacturing error or wear and tear.

In intellectual or abstract contexts, it refers to a breakdown in the chain of reasoning. It suggests that the foundation of an argument is unstable or incorrect, leading to an invalid conclusion. This usage is more clinical and critical than simply calling something wrong.