Sheet (4)
'sheet' is the definition.
(layer is a kind of sheet)
This is the entire clue.
(Other definitions for layer that I've seen before include "Stratum; eg, hen" , "Tier or thickness - or a hen?" , "Single thickness, tier" , "Blanket - single thickness" , "Lamina" .)
'sheet' is the definition.
(I know that plate is a type of sheet)
This is the entire clue.
(Other definitions for plate that I've seen before include "impression" , "trophy" , "Item of crockery" , "Flower" , "Cover with metal" .)
'sheet' is the definition.
(I know that panel is a type of sheet)
This is all the clue.
(Other definitions for panel that I've seen before include "Game show team" , "Discussion group" , "List of doctors" , "Interviewing group" , "- Game; - saw; - pin" .)
'sheet' is the definition.
(I know that pane is a type of sheet glass)
This is all the clue.
(Other definitions for pane that I've seen before include "Single sheet of glass in a window" , "Piece of glass in window" , "Panel of glass" .)