silence vs hush

silence and hush both are nouns.

Word	Noun	Adjective	Verb	Adverb
silence	Yes	No	Yes	No
hush	Yes	No	Yes	No

As nouns, hush is a hyponym of silence; that is, hush is a word with a more specific, narrower meaning than silence:

Other hyponyms of silence include still, stillness, speechlessness, quietness, soundlessness.

As verbs, silence and hush are synonyms defined as:

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

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

silence (verb)	hush (verb)
cause to be quiet or not talk	become quiet or still; fall silent
keep from expression, for example by threats or pressure	cause to be quiet or not talk
	run water over the ground to erode (soil), revealing the underlying strata and valuable minerals
	wash by removing particles
	become quiet or quieter