Graphite or another dark substance used for polishing and darkening metal surfaces, or a verb meaning to apply this substance.
From 'black' + 'lead.' Called this because early workers mistook graphite for a type of lead ore; the misnaming stuck even after the composition was understood.
Blacklead was essential in every household before stainless steel—housemaids spent hours rubbing iron stoves and grates with it to keep them shiny and dark, a tedious job eventually replaced by modern finishes.
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