rate vs fastness

rate and fastness both are nouns.

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

As nouns, fastness is a hyponym of rate; that is, fastness is a word with a more specific, narrower meaning than rate:

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

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