Outside or upper layer (7)
I believe the answer is:
surface
(Other definitions for surface that I've seen before include "Exterior" , "Uppermost layer" , "Outside; rise to the top" , "Top spot" , "Upper limit of liquid" .)
I believe the answer is:
surface
(Other definitions for surface that I've seen before include "Exterior" , "Uppermost layer" , "Outside; rise to the top" , "Top spot" , "Upper limit of liquid" .)