coat vs overcoating

coat and overcoating both are nouns.

Word	Noun	Adjective	Verb	Adverb
coat	Yes	No	Yes	No
overcoating	Yes	No	No	No

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

coat (noun)	overcoating (noun)
growth of hair or wool or fur covering the body of an animal	an additional protective coating (as of paint or varnish)
an outer garment that has sleeves and covers the body from shoulder down; worn outdoors
a thin layer covering something

coat (verb)	overcoating (verb)
cover or provide with a coat
put a coat on; cover the surface of; furnish with a surface
form a coat over