room rate vs rate

room rate and rate both are nouns.

Word	Noun	Adjective	Verb	Adverb
room rate	Yes	No	No	No
rate	Yes	No	Yes	No

As nouns, rate is a hypernym of room rate; that is, rate is a word with a broader meaning than room rate:

Other hypernyms of room rate include charge per unit.

room rate (noun)	rate (noun)
the rate charged daily for a hotel room	the relative speed of progress or change
	amount of a charge or payment relative to some basis
	a quantity or amount or measure considered as a proportion of another quantity or amount or measure
	a magnitude or frequency relative to a time unit

room rate (verb)	rate (verb)
	assign a rank or rating to
	estimate the value of
	be worthy of or have a certain rating