Grating
WordNet
adjective
(1) Unpleasantly harsh or grating in sound
"A gravelly voice"
noun
(2) Optical device consisting of a surface with many parallel grooves in it; disperses a beam of light (or other electromagnetic radiation) into its wavelengths to produce its spectrum
(3) A frame of iron bars to hold a fire
(4) A barrier that has parallel or crossed bars blocking a passage but admitting air