At first I thought this was a great question. I still think it would be great if it was generating responses that could be synonyms.
However, after reading the highest voted answer, "potential refactor point", I feel like I have to say that is not a synonym, and neither are most of the other suggestions!
"Code smell" is good because it describes exactly what the problem is - the code may not be bad itself, it may not be anything on its own , but it is something has been known to indicate that there is a problem lurking somewhere.
The "smell" analogy is so good because if you start "sniffing" at the location of the smell, a good investigator can be led right to the problem!
One case which illustrated this to me well recently was the question Code Smell: Inheritance Abuse. After reading the question and answers, I started to notice inheritance trees in our own code that smelled. They weren't necessarily "potential refactor points" because they were only the surface where problem symptoms became obvious. The real refactor points are deeper underneath, but the investigation started at the inheritance tree.
When you fix the real problem, the smell goes away, just like a bad cabin air filter in a car, or mold within walls.
Just keep using code smell, but use it correctly and lets all try not to overuse it!