bureau vs piece of furniture

bureau and piece of furniture both are nouns.

Word	Noun	Adjective	Verb	Adverb
bureau	Yes	No	No	No
piece of furniture	Yes	No	No	No

As nouns, piece of furniture is a hypernym of bureau; that is, piece of furniture is a word with a broader meaning than bureau:

bureau: furniture with drawers for keeping clothes
piece of furniture: furnishings that make a room or other area ready for occupancy

Other hypernyms of bureau include article of furniture, furniture.

bureau (noun)	piece of furniture (noun)
furniture with drawers for keeping clothes	furnishings that make a room or other area ready for occupancy
an administrative unit of government