Code Smell
In plain terms
A surface sign that code may have deeper problems.
Going deeper
A code smell is a symptom, like duplication or huge functions, that hints at design issues worth refactoring. It's a warning, not a bug itself.
Under the hood
Doesn't break functionality but signals maintainability risk; guides where to refactor.
Examples
Duplicated code, long methods, large classes, god objects, refactoring targets.
Think of it like...
Like a faint odor suggesting something may be spoiling underneath.