Flannel in a dream, at times, might represent the type of garment that you wear, but it could also represent a type of fabric or textile. It symbolizes coziness and protection. The color of the flannel could also be significant. White or cream-colored fabrics can represent purity, while darker colors could symbolize strength and power.
The meaning of a flannel in a dream is that your unconscious may be telling you to take care of your health and that you should dress warmer in the winter than usual. This could be because your environment needs more heating or there is some other underlying health issue that needs attention.
If you find yourself wearing flannels but they keep coming loose, this signifies that you are feeling vulnerable or weak and need help with certain aspects of your life such as schoolwork.
If someone gave you a blue-flowered flannel shirt for Christmas, then this means that they care about you deeply and have good intentions when it comes to helping you succeed in life.