Although they are both gainfully employed, they fit cleaning jobs into their nights and weekends, which is when their service is in most demand any way.
2019年6月四级真题（第一套）听力 Section A
柯林斯高阶英汉双解学习词典释义
ADJ
有收益的；有报酬的
If you are in gainful employment, you have a job for which you are paid.