polish vs blacking

polish and blacking both are nouns.

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

As nouns, blacking is a hyponym of polish; that is, blacking is a word with a more specific, narrower meaning than polish:

polish: a preparation used in polishing
blacking: a substance used to produce a shiny protective surface on footwear

Other hyponyms of polish include shoe polish, Simoniz.

polish (noun)	blacking (noun)
the property of being smooth and shiny	a substance used to produce a shiny protective surface on footwear
a highly developed state of perfection; having a flawless or impeccable quality
a preparation used in polishing

polish (verb)	blacking (verb)
bring to a highly developed, finished, or refined state
improve or perfect by pruning or polishing
make (a surface) shine