health club vs health spa

health club and health spa both are nouns.

Word	Noun	Adjective	Verb	Adverb
health club	Yes	No	No	No
health spa	Yes	No	No	No

As nouns, health club and health spa are synonyms defined as:

health club and health spa: a place of business with equipment and facilities for exercising and improving physical fitness

Other synonyms of health club include spa.

health club (noun)	health spa (noun)
a place of business with equipment and facilities for exercising and improving physical fitness	a place of business with equipment and facilities for exercising and improving physical fitness