strip, lay bare, bared, naked
襢 centers on removing covering to expose what is underneath: stripping, laying bare, or being naked. The meanings all share the idea of making something bare or uncovered.
襢 combines 衤 (clothing) with 亶, which likely contributes the sound. The idea of stripping or baring is associated with clothing being removed.
The clothing radical 衤 beside 亶 suggests a garment being pulled away. Picture a robe being stripped off, leaving the body bare and exposed.
For タン, imagine stripping off a tan-colored cloth: tan -> タン, and the bare skin underneath is revealed.