The phrase "to feel dirty" means to experience a sense of uncleanliness or impurity. It can refer to feeling physically filthy, as if you need to take a shower or wash your hands. However, it can also mean feeling morally tainted or guilty, as if something you did is making you feel ashamed or embarrassed. In either case, the phrase "to feel dirty" indicates an unpleasant sensation of being contaminated or soiled in some way.