gambling casino vs casino

gambling casino and casino both are nouns.

Word	Noun	Adjective	Verb	Adverb
gambling casino	Yes	No	No	No
casino	Yes	No	No	No

As nouns, gambling casino and casino are synonyms defined as:

gambling casino and casino: a public building for gambling and entertainment

gambling casino (noun)	casino (noun)
a public building for gambling and entertainment	a card game in which cards face up on the table are taken with eligible cards in the hand
	a public building for gambling and entertainment