decrease vs decrement

decrease and decrement both are nouns.

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

As nouns, decrease and decrement are synonyms defined as:

As nouns, decrease and decrement are synonyms defined as:

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

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