Synonyms for Silence (same or very similar meaning)
WordNet sense 1 (the absence of sound):
quietWordNet sense 2 (the trait of keeping things secret):
secrecy, secretivenessWordNet sense 3 (a refusal to speak when expected):
mutenessWordNet sense 4 (cause to be quiet or not talk):
hush, still, quieten, shut up, hush upFrom the ODE community, based on WordNetadd/edit