suppress vs decrease

suppress is not a noun while decrease is a noun.

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

As verbs, decrease is a hypernym of suppress; that is, decrease is a word with a broader meaning than suppress:

Other hypernyms of suppress include lessen, minify.

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

suppress (verb)	decrease (verb)
bring under control by force or authority	decrease in size, extent, or range
lessen to the point of stopping	make become smaller
put out of one's consciousness
consciously restrain from showing; of emotions, desires, impulses, or behavior
come down on or keep down by unjust use of one's authority