blacking

noun

1. (uncountable, usually)A preparation, containing lampblack, used to produce a shiny black coating.
2. (uncountable, usually)Shoe polish.
3. (uncountable, usually)A boycott, usually as part of an industrial dispute.

   “Instead, the unions persisted in believing they could defeat Murdoch through a unified campaign of picket lines, blackings and boycotts.”

verb

1. (form-of, gerund, participle, present)present participle and gerund of black