grating vs overpass

grating

noun
  • A barrier that has parallel or crossed bars blocking a passage but admitting air. 

  • An optical system of close equidistant and parallel lines or bars, especially lines ruled on a polished surface, used for producing spectra by diffraction. 

  • The strong wooden lattice used to cover a hatch, admitting light and air; also, a movable lattice used for the flooring of boats. 

  • A frame of iron bars to hold a fire. 

  • The sound made by something that grates against something else. 

  • The loose material that comes from something being grated. 

adj
  • Harsh and unpleasant. 

  • Abrasive; tending to annoy. 

overpass

noun
  • A section of a road or path that crosses over an obstacle, especially another road, railway, etc. 

verb
  • To pass above something, as when flying or moving on a higher road. 

  • To exceed, overstep, or transcend a limit, threshold, or goal. 

  • To disregard, skip, or miss something. 

How often have the words grating and overpass occurred in a corpus of books? (source: Google Ngram Viewer )