Single thickness of a substance lying over or under another (5)
I believe the answer is:
layer
(Other definitions for layer that I've seen before include "(Separate) level" , "Seam" , "Single thickness, tier" , "Bed - hen" , "Coating" .)
I believe the answer is:
layer
(Other definitions for layer that I've seen before include "(Separate) level" , "Seam" , "Single thickness, tier" , "Bed - hen" , "Coating" .)