spacing vs rate

spacing and rate both are nouns.

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

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

spacing (noun)	rate (noun)
the property possessed by an array of things that have space between them	the relative speed of progress or change
the time between occurrences of a repeating event	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

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