shut up vs silence

shut up is not a noun while silence is a noun.

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

As verbs, shut up and silence are synonyms defined as:

Other synonyms of shut up include hush, hush up, quieten, still.

shut up (noun)	silence (noun)
	the absence of sound
	a refusal to speak when expected
	the trait of keeping things secret
	the state of being silent (as when no one is speaking)

shut up (adjective)	silence (adjective)
closely confined

shut up (verb)	silence (verb)
cause to be quiet or not talk	cause to be quiet or not talk
refuse to talk or stop talking; fall silent	keep from expression, for example by threats or pressure
place in a place where something cannot be removed or someone cannot escape