1.Fig. unpleasant or uninteresting work. My boss does all the traveling. I get all the dirty work to do.She's tired of doing all the dirty work at the office.
2.Fig. dishonest or underhanded actions; treachery. She knew there was some dirty work going on when she saw her opponents whispering together.The company seems respectable enough, but there's a lot of dirty work that goes on.
An unpleasant, distasteful, or thankless task or job. For example, Jane complained that she had to do all the dirty work while her colleagues took long vacations . [First half of 1900s]