gambling house vs gambling den

gambling house and gambling den both are nouns.

Word	Noun	Adjective	Verb	Adverb
gambling house	Yes	No	No	No
gambling den	Yes	No	No	No

As nouns, gambling house and gambling den are synonyms defined as:

gambling house and gambling den: a public building in which a variety of games of chance can be played (operated as a business)

Other synonyms of gambling house include gambling hell, gaming house.

gambling house (noun)	gambling den (noun)
a public building in which a variety of games of chance can be played (operated as a business)	a public building in which a variety of games of chance can be played (operated as a business)