That's not quite what code smell means. It comes from the common idiom that "something doesn't smell right" (https://www.englishidiom.com/glossary/something-doesnt-smell-right/) and in the context of code it refers to the feeling that an experienced developer gets when looking at a piece of code and can see that it 'looks wrong', without necessarily being immediately able to identify the specific problem. Possibly it ends up just being sloppy coding style, but often sloppy coding is an indicator of sloppy thinking, so there is a correlation, there.