Evil or negative impulses are often represented in dreams as things or people being dirty. In the search for spirituality we may often feel dirty or contaminated by such negativity.
Psychological / Emotional Perspective:
To be dirty in a dream may indicate that we are not at ease with our own bodily functions. If someone we know has made us dirty or contaminated us it is an indication not to trust that person.
Everyday Material Aspects:
We will dream of being dirty when we are not operating within our own principles or when someone else’s action has put us in a situation which we find compromises us.