Simply seeing underwear being neatly folded signifies that there will be a lot of rumors about you and your actions. These rumors will not be able to tarnish your reputation however and you will not be affected to a great degree.
Seeing dirty underwear in the dream points to malicious rumors that will cause some harm to your reputation. If this dream has a recurring nature it means that the rumors will cause a more lasting harm. You will need to work hard in order to remove the blemishes from your reputation.
Seeing underwear on a clothes line drying, means that a conflict with members of your more distant family is possible. If you hang underwear on a line for drying it means that some sizeable victory will occur in your life. This will likely be connected to law and courts and the victory will likely be of legal nature.
If you dream that you are wearing quite expensive underwear it means that your expectations about someone in the real life will not be in vain. You will be quite pleased to know that they indeed care for your well being a lot.
Washing your own underwear in the dream means that you will soon feel ashamed of something in your personal life. If have this dream in the early hours of the morning it indicates that the act that will the reason for your shame will happen sooner, most likely in the next few days.
If you wear new underwear in the dream it means that a new stage in the relationship with your partner will be reached. It you are not in a relationship this dream means that you will soon enter into a relationship which will progress quite rapidly.