suppress vs shut up

suppress is not an adjective while shut up is an adjective.

Word	Noun	Adjective	Verb	Adverb
suppress	No	No	Yes	No
shut up	No	Yes	Yes	No

As verbs, shut up is a hyponym of suppress; that is, shut up is a word with a more specific, narrower meaning than suppress:

suppress (adjective)	shut up (adjective)
	closely confined

suppress (verb)	shut up (verb)
bring under control by force or authority	cause to be quiet or not talk
lessen to the point of stopping	refuse to talk or stop talking; fall silent
put out of one's consciousness	place in a place where something cannot be removed or someone cannot escape
consciously restrain from showing; of emotions, desires, impulses, or behavior
come down on or keep down by unjust use of one's authority