Grat"ing (?), n. [See 2d Grate.]
1.
A partition, covering, or frame of parallel or cross bars; a latticework resembling a window grate; as, the grating of a prison or convent.
2. (Optics)
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.
3. pl. (Naut.)
The strong wooden lattice used to cover a hatch, admitting light and air; also, a movable Lattice used for the flooring of boats.
[1913 Webster]
© Webster 1913
Grat"ing, a. [See Grate to rub harshy.]
That grates; making a harsh sound; harsh. -- Grat"ing*ly, adv.
© Webster 1913
Grat"ing, n.
A harsh sound caused by attrition.
© Webster 1913
Grat"ing (?), n. (Optics)
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.
© Webster 1913