With one reversal, the answer is triple layered
I believe the answer is:
three-ply
'layered' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for three-ply that I've seen before include "Having a triple layer" , "Type of wood or wool" , "Measure of thickness (of wood or wool)" .)