The Vietnamese word "lủn mủn" refers to being petty or mean in disposition. It describes someone who tends to focus on trivial matters or is overly concerned with insignificant details, often at the expense of more important issues.
In more advanced contexts, you can use "lủn mủn" to discuss not just personal traits but also societal behaviors, such as how people may argue over small issues instead of addressing larger concerns.
While "lủn mủn" primarily indicates pettiness or meanness, it can also imply a lack of attention to important matters because of an excessive focus on trivialities.