ˈgrād.]iŋ, -āt], ]ēŋ\ noun
( -s )
Etymology: grate (I) + -ing
1. : a partition, covering, or frame of parallel bars or crossbars : a latticework resembling a window grate : grate 2
2.
a. : a strong usually wooden lattice used on shipboard in fair weather to cover a hatch and still admit light and air
b. : a movable lattice used for flooring (as of a boat)
c. gratings plural : the openwork metal floors and platforms of an engine room and boiler room in a ship
3. : a system of close equidistant and parallel lines or bars (as ruled on a polished surface) used for producing spectra by diffraction