Washing underwear in a dream means that you have something to be ashamed of and something that you would like to hide from others. Dirty underwear warns that you are a subject of the various gossips, to which you have given a reason.
Dreaming about beautiful underwear means that in real life you can be called connoisseurs. You know a lot about art and have an innate taste. For a young woman, a dream in which she irons her underwear means that she will have a successful marriage.