fastness vs rate

fastness and rate both are nouns.

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

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

Other hypernyms of fastness include pace.

fastness (noun)	rate (noun)
a strongly fortified defensive structure	the relative speed of progress or change
a rate (usually rapid) at which something happens	amount of a charge or payment relative to some basis
the quality of being fixed in place as by some firm attachment	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

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