Hide monitor (6)
I believe the answer is:
screen
This clue is a double definition.
'hide' is the first definition.
(I've seen this in another clue)
'monitor' is the second definition.
(I know that monitor can be written as screen)
(Other definitions for screen that I've seen before include "Protective frame" , "Onto which pictures are projected" , "Room partition; vet" , "Blind - hide from view" , "Sheltering row of trees" .)