Underwear is traditionally read as what is private and close to the skin — secrets, intimacy, the hidden layer. Being seen in it speaks of a fear of exposure rather than anything literal. Choosing new underwear is usually read as a change in self-image or confidence. Dirty or torn underwear is linked to embarrassment or something you would rather keep hidden, while elegant underwear points to sensuality and self-worth. Dream books treat it as the layer only you know about. It can help to ask what part of yourself feels exposed right now.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.