brass vs ormolu

brass and ormolu both are nouns.

Word	Noun	Adjective	Verb	Adverb
brass	Yes	No	No	No
ormolu	Yes	No	No	No

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

brass (noun)	ormolu (noun)
a wind instrument that consists of a brass tube (usually of variable length) that is blown by means of a cup-shaped or funnel-shaped mouthpiece	brass that looks like gold; used to decorate furniture
a memorial made of brass
an ornament or utensil made of brass
impudent aggressiveness
the persons (or committees or departments etc.) who make up a body for the purpose of administering something
the section of a band or orchestra that plays brass instruments
an alloy of copper and zinc