slag vs sullage

slag

noun
  • Scum that forms on the surface of molten metal. 

  • Scoria associated with a volcano. 

  • A prostitute, or a woman who acts like one; a slut. 

  • Waste material from a mine. 

  • Hard aggregate remaining as a residue from blast furnaces, sometimes used as a surfacing material. 

  • Impurities formed and separated out when a metal is smelted from ore; vitrified cinders. 

  • A contemptible person, a scumbag. 

verb
  • To spit. 

  • To become slag; to agglomerate when heated below the fusion point. 

  • To reduce to slag. 

  • To talk badly about; to malign or denigrate (someone). 

  • To produce slag. 

sullage

noun
  • The scoria on the surface of molten metal in the ladle. 

  • Silt or sediment deposited from flowing water. 

  • That which sullies or defiles. 

  • The liquid discharges from kitchens, washbasins, toilets etc; sewage. 

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