shellac varnish vs varnish

shellac varnish and varnish both are nouns.

Word	Noun	Adjective	Verb	Adverb
shellac varnish	Yes	No	No	No
varnish	Yes	No	Yes	No

As nouns, varnish is a hypernym of shellac varnish; that is, varnish is a word with a broader meaning than shellac varnish:

shellac varnish: a thin varnish made by dissolving lac in ethanol; used to finish wood
varnish: a coating that provides a hard, lustrous, transparent finish to a surface

shellac varnish (noun)	varnish (noun)
a thin varnish made by dissolving lac in ethanol; used to finish wood	a coating that provides a hard, lustrous, transparent finish to a surface

shellac varnish (verb)	varnish (verb)
	cover with varnish