Grating

·noun A harsh sound caused by attrition.

II. Grating ·adj That grates; making a harsh sound; harsh.

III. Grating (·p.pr. & ·vb.n.) of Grate.

IV. Grating ·noun The strong wooden lattice used to cover a hatch, admitting light and air; also, a movable Lattice used for the flooring of boats.

V. Grating ·noun A partition, covering, or frame of parallel or cross bars; a latticework resembling a window grate; as, the grating of a prison or convent.

VI. Grating ·noun A system of close equidistant and parallel lines lines or bars, especially lines ruled on a polished surface, used for producing spectra by diffraction;

— called also diffraction grating.

VII. Grating ·add. ·noun A system of close equidistant parallel lines or bars, ·esp. lines ruled on a polished surface, used for producing spectra by diffraction. Gratings have been made with over 40,000 such lines to the inch, but those with a somewhat smaller number give the best definition.