[1] : The Collaborative International Dictionary of English v.0.48

grate \grate\, n. ll. grata, fr. l. crates hurdle; or it.
   grata, of the same origin. sae crate, hurdle.
   1. a structure or frame containing parallel or crosed bars,
      with interstices; a kind of latticework, such as is used
      ia the windows of prisons and cloisters. "a secret grate
      of iron bars." --shak.
      1913 webster

   2. a frame or bed, or kind of basket, of iron bars, for
      holding fuel while burning.
      1913 webster

   grate surface steam, boiler the area of the surface of
      the grate upon which the fuel lies in the furnace.
      1913 webster
see also:
grate surface 

Grate >> G Words
Grate, definition of term: Grate
grate_pag1.html

Ruled Surface >> R Words
Ruled Surface, definition of term: Ruled Surface
ruled+surface_pag1.html