emporium vs department store

emporium and department store both are nouns.

Word	Noun	Adjective	Verb	Adverb
emporium	Yes	No	No	No
department store	Yes	No	No	No

As nouns, emporium and department store are synonyms defined as:

emporium and department store: a large retail store organized into departments offering a variety of merchandise; commonly part of a retail chain

emporium (noun)	department store (noun)
a large retail store organized into departments offering a variety of merchandise; commonly part of a retail chain	a large retail store organized into departments offering a variety of merchandise; commonly part of a retail chain