Toilet paper layer (3)
I believe the answer is:
ply
'toilet paper layer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ply that I've seen before include "Work steadily at, say trade" , "Use or wield, tool or weapon" , "Laminate thickness" , "Work steadily as at one's trade" , "Work steadily at the strand or layer" .)