department store vs outlet

department store and outlet both are nouns.

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

As nouns, outlet is a hypernym of department store; that is, outlet is a word with a broader meaning than department store:

department store: a large retail store organized into departments offering a variety of merchandise; commonly part of a retail chain
outlet: a place of business for retailing goods

Other hypernyms of department store include mercantile establishment, retail store, sales outlet.

department store (noun)	outlet (noun)
a large retail store organized into departments offering a variety of merchandise; commonly part of a retail chain	activity that frees or expresses creative energy or emotion
	an opening that permits escape or release
	a place of business for retailing goods
	receptacle providing a place in a wiring system where current can be taken to run electrical devices