blacking vs shoe polish

blacking and shoe polish both are nouns.

Word	Noun	Adjective	Verb	Adverb
blacking	Yes	No	No	No
shoe polish	Yes	No	No	No

As nouns, blacking and shoe polish are synonyms defined as:

blacking and shoe polish: a substance used to produce a shiny protective surface on footwear

blacking (noun)	shoe polish (noun)
a substance used to produce a shiny protective surface on footwear	a substance used to produce a shiny protective surface on footwear