Irritating grid (7)
I believe the answer is:
grating
I believe this is a double definition.
'irritating' is the first definition.
(grating is a kind of irritating)
'grid' is the second definition.
(thesaurus)
(Other definitions for grating that I've seen before include "Jarring" , "Frame of iron bars to block passage but allow air" , "Irritating - framework of bars" , "Unpleasantly harsh in sound" , "Frame of bars supporting a fire" .)