rate of pay vs rate

rate of pay and rate both are nouns.

Word	Noun	Adjective	Verb	Adverb
rate of pay	Yes	No	No	No
rate	Yes	No	Yes	No

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

Other hypernyms of rate of pay include charge per unit.

rate of pay (noun)	rate (noun)
amount of money received per unit time	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

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