Protective eyelet (7)
I believe the answer is:
grommet
'protective eyelet' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for grommet that I've seen before include "Eyelet's metal ring" , "Tube in eardrum to drain and ventilate ear" , "Washer; eyelet" , "Ring shaped to line a small hole" , "Eyelet lining a small hole" .)