The Collaborative International Dictionary of English v.0.48:

Silence \Si"lence\, n. [F., fr. L. silentium. See Silent.]
   [1913 Webster]
   1. The state of being silent; entire absence of sound or
      noise; absolute stillness.
      [1913 Webster]

            I saw and heared; for such a numerous host
            Fled not in silence through the frighted deep.
                                                  --Milton.
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   2. Forbearance from, or absence of, speech; taciturnity;
      muteness.
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   3. Secrecy; as, these things were transacted in silence.
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            The administration itself keeps a profound silence.
                                                  --D. Webster.
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   4. The cessation of rage, agitation, or tumilt; calmness;
      quiest; as, the elements were reduced to silence.
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   5. Absence of mention; oblivion.
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            And what most merits fame, in silence hid. --Milton.
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The Collaborative International Dictionary of English v.0.48:

Silence \Si"lence\, interj.
   Be silent; -- used elliptically for let there be silence, or
   keep silence. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Silence \Si"lence\, v. t. [imp. & p. p. Silenced; p. pr. & vb.
   n. Silencing.]
   1. To compel to silence; to cause to be still; to still; to
      hush.
      [1913 Webster]

            Silence that dreadful bell; it frights the isle.
                                                  --Shak.
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   2. To put to rest; to quiet.
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            This would silence all further opposition.
                                                  --Clarendon.
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            These would have silenced their scruples. --Rogers.
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   3. To restrain from the exercise of any function, privilege
      of instruction, or the like, especially from the act of
      preaching; as, to silence a minister of the gospel.
      [1913 Webster]

            The Rev. Thomas Hooker of Chelmsford, in Essex, was
            silenced for nonconformity.           --B. Trumbull.
      [1913 Webster]

   4. To cause to cease firing, as by a vigorous cannonade; as,
      to silence the batteries of an enemy.
      [1913 Webster]

WordNet (r) 3.0 (2006):

silence
    n 1: the state of being silent (as when no one is speaking);
         "there was a shocked silence"; "he gestured for silence"
    2: the absence of sound; "he needed silence in order to sleep";
       "the street was quiet" [syn: silence, quiet] [ant:
       sound]
    3: a refusal to speak when expected; "his silence about my
       contribution was surprising" [syn: muteness, silence]
    4: the trait of keeping things secret [syn: secrecy,
       secretiveness, silence]
    v 1: cause to be quiet or not talk; "Please silence the children
         in the church!" [syn: hush, quieten, silence,
         still, shut up, hush up] [ant: louden]
    2: keep from expression, for example by threats or pressure;
       "All dissenters were silenced when the dictator assumed
       power"

Moby Thesaurus II by Grady Ward, 1.0:

218 Moby Thesaurus words for "silence":
   answer, answer conclusively, argue down, asphyxiate, ataraxia,
   ataraxy, blow to pieces, blow up, blunt, bottle up, brain, brevity,
   briefness, bring down, brusqueness, burn to death, calm, calmness,
   censor, choke, choke off, clamp down on, composure, conciseness,
   confound, confute, contemplation, contradict, controvert, cork,
   cork up, crack down on, crush, curtains, curtness, cut down,
   cut to pieces, damp, damp down, dampen, deaden, deal a deathblow,
   decease, deck, defeat, deflate, demise, demolish, deny, disarm,
   disintegrate, dismiss, dispose of, dissolution, drop, drown, dumb,
   dumbfound, dumbness, economy of words, emasculate, enchain,
   extinguish, fell, finish, floor, frag, gag, give the quietus,
   gun down, hamstring, handcuff, hobble, hog-tie, hold down,
   hugger-mugger, hugger-muggery, hush, hush-hush, imperturbability,
   incinerate, inhibit, jugulate, jump on, keep down, keep under,
   kill, knock out, laconicalness, laconism, lapidate, lay low,
   lucid stillness, lull, manacle, marmoreal repose, mitigate,
   mollify, muffle, mute, muteness, muzzle, nirvana, noiselessness,
   nonplus, obmutescence, overcome, overmaster, overmatch, overpower,
   overset, overthrow, overturn, overwhelm, pacify, paralyze, parry,
   passing, pauciloquy, peace, peacefulness, pistol, placidity,
   placidness, poleax, pour water on, propitiate, prostrate, put down,
   put out, put to silence, quash, quell, quench, quiescence,
   quiescency, quiet, quieten, quietism, quietness, quietude, quietus,
   rebut, reduce to silence, refute, repose, repress, rest,
   restfulness, restrain, reticence, riddle, satori, secretiveness,
   secretness, send flying, serenity, settle, shoot, shoot down,
   shoot to death, shortness, shotgun, shush, shut down on, shut off,
   shut up, silken repose, sit down on, sit on, sleep, slumber, smash,
   smash all opposition, smother, snuff out, soft-pedal, soothe,
   soundlessness, sparingness of words, speechlessness, squash,
   squelch, stab to death, stamp out, stanch, stifle, still,
   stillness, stone, stone to death, strangle, strike dead,
   strike dumb, stultify, subdue, subvert, suffocate, suppress,
   surmount, taciturnity, temper, terseness, throttle, trample out,
   trample underfoot, tranquillity, trip, trip up, truss up,
   uncommunicativeness, undermine, unloquaciousness, untalkativeness,
   upset, vaporize, wise passiveness, wordlessness



Bouvier's Law Dictionary, Revised 6th Ed (1856):

SILENCE. The state of a person who does not speak, or of one who refrains
from speaking.
     2. Pure and simple silence cannot be considered as a consent to a
contract, except in cases when the silent person is bound in good faith to
explain himself, in which case, silence gives consent. 6 Toull. liv. 3, t.
3, n. 32, note; 14 Serg. & Rawle, 393; 2 Supp. to Ves. jr. 442; 1 Dane's Ab.
c. 1, art. 4, Sec. 3; 8 T. R. 483; 6 Penn. St. R. 336; 1 Greenl. Ev. 201; 2
Bouv. Inst. n. 1313. But no assent will be inferred from a man's silence,
unless, 1st. He knows his rights and knows what he is doing and, 2d. His
silence is voluntary.
     3. When any person is accused of a crime, or charged with any fact, and
he does not deny it, in general, the presumption is very strong that the
charge is correct. 7 C. & P. 832 5 C. & P. 332; Joy on Conf. s. 10, p. 77.
     4. The rule does not extend to the silence of a prisoner, when on his
examination before a magistrate he is charged by another prisoner with
having joined him in the commission of an offence: 3 Stark. C. 33.
     5. When an oath is administered to a witness, instead of expressly
promising to keep it, he gives his assent by his silence, and kissing the
book.
     6. The person to be affected by the silence must be one not
disqualified to act as non compos, an infant, or the like, for even the
express promise of such a person would not bind him to the performance of
any contract.
     7. The rule of the civil law is that silence is not an acknowledgment
or denial in every case, qui tacet, non utique fatetur: sed tamen verum est,
eum non negaro. Dig. 50, 17, 142.