Plastering strip (4)
I believe the answer is:
lath
'plastering strip' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lath that I've seen before include "Narrow thin strip of wood" , "Thin strip of wood used in plastering" , "Halt bearing strip of wood" , "Strip of wood used with plaster" , "A thin strip of wood as for making furniture" .)