#flat  a level tract of land
  supertype:  #plain__champaign  extensive tract of level open land; "they emerged from the woods onto a vast open plain"; "he longed for the fields of his youth"
  subtype:  #salt_flat__salt_plain  a flat expanse of salt left by the evaporation of a body of salt water

No statement uses or specializes #flat; click here to add one.