decrease vs rarefaction

decrease and rarefaction both are nouns.

Word	Noun	Adjective	Verb	Adverb
decrease	Yes	No	Yes	No
rarefaction	Yes	No	No	No

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

Other hyponyms of decrease include shrinkage, shrinking, casualty, sinking, attrition, dwindling, dwindling away, waning.

decrease (noun)	rarefaction (noun)
the act of decreasing or reducing something	a decrease in the density of something
the amount by which something decreases
a change downward
a process of becoming smaller or shorter

decrease (verb)	rarefaction (verb)
decrease in size, extent, or range
make become smaller