bier vs catafalque

bier and catafalque both are nouns.

Word	Noun	Adjective	Verb	Adverb
bier	Yes	No	No	No
catafalque	Yes	No	No	No

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

bier: a stand to support a corpse or a coffin prior to burial
catafalque: a decorated bier on which a coffin rests in state during a funeral

bier (noun)	catafalque (noun)
a stand to support a corpse or a coffin prior to burial	a decorated bier on which a coffin rests in state during a funeral
a coffin along with its stand