cover, covering, screening, masking -- (the act of concealing the existence of something by obstructing the view of it; "the cover concealed their guns from enemy aircraft")
masking -- (the blocking of one sensation resulting from the presence of another sensation; "he studied auditory masking by pure tones")
masking piece, masking -- (scenery used to block the audience's view of parts of the stage that should not be seen)
Overview of verb mask
The verb mask has 5 senses
dissemble, cloak, mask -- (hide under a false appearance; "He masked his disappointment")
mask -- (put a mask on or cover with a mask; "Mask the children for Halloween")
disguise, mask -- (make unrecognizable; "The herb masks the garlic taste"; "We disguised our faces before robbing the bank")