The Collaborative International Dictionary of English v.0.48:

Dismiss \Dis*miss"\, n.
   Dismission. [Obs.] --Sir T. Herbert.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dismiss \Dis*miss"\, v. t. [imp. & p. p. Dismissed; p. pr. &
   vb. n. Dismissing.] [L. dis- + missus, p. p. of mittere to
   send: cf. dimittere, OF. desmetre, F. d['e]mettre. See
   Demise, and cf. Dimit.]
   1. To send away; to give leave of departure; to cause or
      permit to go; to put away.
      [1913 Webster]

            He dismissed the assembly.            --Acts xix.
                                                  41.
      [1913 Webster]

            Dismiss their cares when they dismiss their flock.
                                                  --Cowper.
      [1913 Webster]

            Though he soon dismissed himself from state affairs.
                                                  --Dryden.
      [1913 Webster]

   2. To discard; to remove or discharge from office, service,
      or employment; as, the king dismisses his ministers; the
      matter dismisses his servant.
      [1913 Webster]

   3. To lay aside or reject as unworthy of attentions or
      regard, as a petition or motion in court.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dismiss
    v 1: bar from attention or consideration; "She dismissed his
         advances" [syn: dismiss, disregard, brush aside,
         brush off, discount, push aside, ignore]
    2: cease to consider; put out of judicial consideration; "This
       case is dismissed!" [syn: dismiss, throw out]
    3: stop associating with; "They dropped her after she had a
       child out of wedlock" [syn: dismiss, send packing, send
       away, drop]
    4: terminate the employment of; discharge from an office or
       position; "The boss fired his secretary today"; "The company
       terminated 25% of its workers" [syn: displace, fire,
       give notice, can, dismiss, give the axe, send away,
       sack, force out, give the sack, terminate] [ant:
       employ, engage, hire]
    5: end one's encounter with somebody by causing or permitting
       the person to leave; "I was dismissed after I gave my report"
       [syn: dismiss, usher out]
    6: declare void; "The President dissolved the parliament and
       called for new elections" [syn: dissolve, dismiss]

Moby Thesaurus II by Grady Ward, 1.0:

274 Moby Thesaurus words for "dismiss":
   abandon, abjure, absolve, acquit, amnesty, answer,
   answer conclusively, argue down, ax, banish, beat back, belittle,
   boot, boot out, bounce, bow out, break, break up, brush aside,
   brush off, bump, bundle, bundle off, bust, can, cashier, cast,
   cast loose, chase, chase away, chase off, chuck, chuck out, clear,
   confound, confute, contemn, contradict, controvert, crush, cut,
   cut dead, deactivate, debrief, decline, deconsecrate,
   decontaminate, defeat, defrock, degrade, demob, demobilize,
   demolish, demote, deny, deplume, depose, deprive, deride, deselect,
   despise, destigmatize, detach, dethrone, diminish, disapprove,
   disband, disbar, discard, discharge, disclaim, discount, discrown,
   disdain, disemploy, disenthrone, disintegrate, disorganize, disown,
   dispense from, disperse, displace, displume, dispose of, disregard,
   dissolve, drive away, drive back, drop, drop the subject, drum out,
   eject, evict, except, exclude, excommunicate, exculpate, excuse,
   exempt, exempt from, exonerate, expel, extrude, fend off, finish,
   fire, floor, flout, forget, forget about it, forget it, forgive,
   forswear, free, furlough, gibe, gird, give absolution,
   give the air, give the ax, give the gate, give the go-by,
   go bail for, go separate ways, grant amnesty to, grant bail to,
   grant immunity, grant remission, have done with, hold off,
   hustle out, ignore, jeer, justify, keep off, kick, kick out,
   kick upstairs, lay aside, lay off, let go, let go free, let it go,
   let loose, let off, let out, let slip, liquidate,
   look right through, make little of, make redundant, mock,
   muster out, neglect, nonplus, nonpros, oust, out, overlook,
   overthrow, overturn, overwhelm, pack off, pardon, parole, parry,
   part, part company, pass by, pass up, pension, pension off,
   pooh-pooh, purge, push aside, push back, put aside, put away,
   put back, put on parole, put to silence, quash the charge, rally,
   read out of, rebuff, rebut, recant, reduce to silence, refuse,
   refuse to acknowledge, refuse to consider, refuse to recognize,
   refute, reject, release, remit, remove, remove from office,
   renounce, repel, replace, reprobate, repudiate, repulse, retire,
   ridicule, riff, sack, scatter, scoff, scorn, scout, send away,
   send off, send packing, separate, separate forcibly, set aside,
   set free, settle, shed, shove away, show the door, show the gate,
   shrive, shrug off, shut up, silence, slight, slough,
   smash all opposition, sneeze at, snub, split up, spurn, squash,
   squelch, strip, strip of office, strip of rank, subvert,
   superannuate, surplus, suspend, taunt, terminate, think nothing of,
   throw away, throw out, thrust aside, thrust back, toss out,
   turn away, turn away from, turn back, turn down, turn off,
   turn out, twit, unchurch, undermine, unfrock, unhand, unmarry,
   unsaddle, unseat, unthrone, upset, vindicate, waive, ward off,
   whitewash, withdraw the charge, write off