decrease vs free fall

decrease and free fall both are nouns.

Word	Noun	Adjective	Verb	Adverb
decrease	Yes	No	Yes	No
free fall	Yes	No	No	No

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

Other hyponyms of decrease include dip, drop, fall, shrinkage.

decrease (noun)	free fall (noun)
the act of decreasing or reducing something	a sudden sharp decrease in some quantity
the amount by which something decreases	the ideal falling motion of something subject only to a gravitational field
a change downward
a process of becoming smaller or shorter

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