religious holiday vs holiday

religious holiday and holiday both are nouns.

Word	Noun	Adjective	Verb	Adverb
religious holiday	Yes	No	No	No
holiday	Yes	No	Yes	No

As nouns, holiday is a hypernym of religious holiday; that is, holiday is a word with a broader meaning than religious holiday:

religious holiday (noun)	holiday (noun)
a day specified for religious observance	leisure time away from work devoted to rest or pleasure
	a day on which work is suspended by law or custom

religious holiday (verb)	holiday (verb)
	spend or take a vacation