The Collaborative International Dictionary of English v.0.48:

Appearance \Ap*pear"ance\, n. [F. apparence, L. apparentia, fr.
   apparere. See Appear.]
   1. The act of appearing or coming into sight; the act of
      becoming visible to the eye; as, his sudden appearance
      surprised me.
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   2. A thing seed; a phenomenon; a phase; an apparition; as, an
      appearance in the sky.
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   3. Personal presence; exhibition of the person; look; aspect;
      mien.
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            And now am come to see . . .
            It thy appearance answer loud report. --Milton.
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   4. Semblance, or apparent likeness; external show. pl.
      Outward signs, or circumstances, fitted to make a
      particular impression or to determine the judgment as to
      the character of a person or a thing, an act or a state;
      as, appearances are against him.
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            There was upon the tabernacle, as it were, the
            appearance of fire.                   --Num. ix. 15.
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            For man looketh on the outward appearance. --1 Sam.
                                                  xvi. 7.
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            Judge not according to the appearance. --John. vii.
                                                  24.
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   5. The act of appearing in a particular place, or in society,
      a company, or any proceedings; a coming before the public
      in a particular character; as, a person makes his
      appearance as an historian, an artist, or an orator.
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            Will he now retire,
            After appearance, and again prolong
            Our expectation?                      --Milton.
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   6. Probability; likelihood. [Obs.]
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            There is that which hath no appearance. --Bacon.
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   7. (Law) The coming into court of either of the parties; the
      being present in court; the coming into court of a party
      summoned in an action, either by himself or by his
      attorney, expressed by a formal entry by the proper
      officer to that effect; the act or proceeding by which a
      party proceeded against places himself before the court,
      and submits to its jurisdiction. --Burrill. --Bouvier.
      --Daniell.
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   To put in an appearance, to be present; to appear in
      person.

   To save appearances, to preserve a fair outward show.
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   Syn: Coming; arrival; presence; semblance; pretense; air;
        look; manner; mien; figure; aspect.
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WordNet (r) 3.0 (2006):

appearance
    n 1: outward or visible aspect of a person or thing [syn:
         appearance, visual aspect]
    2: the event of coming into sight [ant: disappearance]
    3: formal attendance (in court or at a hearing) of a party in an
       action [syn: appearance, appearing, coming into court]
    4: a mental representation; "I tried to describe his appearance
       to the police"
    5: the act of appearing in public view; "the rookie made a brief
       appearance in the first period"; "it was Bernhardt's last
       appearance in America" [ant: disappearance, disappearing]
    6: pretending that something is the case in order to make a good
       impression; "they try to keep up appearances"; "that ceremony
       is just for show" [syn: appearance, show]

Moby Thesaurus II by Grady Ward, 1.0:

203 Moby Thesaurus words for "appearance":
   Christophany, Masan, Prospero, Satanophany, accomplishment,
   achievement, acting, advent, affectation, air, airiness,
   angelophany, apparent character, apparition, appearances, approach,
   arrival, aspect, astral, astral spirit, attainment, attitudinizing,
   avatar, banshee, bearing, bluff, bluffing, cheating, color,
   coloring, coming, control, countenance, deception, delusion,
   delusiveness, demeanor, departed spirit, disclosure,
   disembodied spirit, disguise, display, dissemblance, dissembling,
   dissemination, dissimulation, duppy, dybbuk, eidolon, embodiment,
   epiphany, evidence, evincement, expression, exteriority, exteriors,
   external appearance, externality, externalness, externals,
   extrinsicality, facade, face, fakery, faking, fallaciousness,
   false air, false appearance, false front, false image, false light,
   false show, falseness, falsity, fantasy, features, feigning, feint,
   fiction, figure, foreignness, form, four-flushing, fraud, front,
   gaudiness, ghost, gilt, gloss, grateful dead, guide, guise, hant,
   haunt, hint, humbug, humbuggery, idealization, idolum, illusion,
   illusionism, illusionist, illusiveness, image, immateriality,
   imposture, incarnation, incorporeal, incorporeal being,
   incorporeity, indication, larva, lemures, lineaments, look, looks,
   magic, magic act, magic show, magician, make-believe, manes,
   manifestation, manner, masquerade, materialization, mere externals,
   meretriciousness, mien, mirage, oni, openness, ostent, ostentation,
   outerness, outside, outward appearance, outward show, outwardness,
   phantasm, phantasma, phantasmagoria, phantom, phasm, phenomenon,
   playacting, pneumatophany, poltergeist, pose, posing, posture,
   presence, prestidigitation, pretense, pretension, pretext, proof,
   public image, publication, reaching, representation, revelation,
   revenant, seeming, semblance, shade, shadow, shallowness, sham,
   shape, show, showing, shrouded spirit, simulacrum, simulation,
   sleight of hand, sorcerer, sorcery, specious appearance,
   speciousness, specter, spectral ghost, spirit, spook, sprite,
   suggestion, superficiality, surface appearance, surface show,
   theophany, unactuality, unreality, unsubstantiality, vain show,
   varnish, vision, waking dream, walking dead man, wandering soul,
   wildest dream, window dressing, wraith, zombie



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

APPEARANCE, practice. Signifies the filing common or special bail to the
action.
     2. The appearance, with all other subsequent pleadings supposed to take
place in court, should (in accordance with the ancient practice) purport to
be in term time. It is to be observed, however, that though the proceedings
are expressed as if occurring in term time, yet, in fact, much of the
business is now done, in periods of vacation.
     3. The appearance of the parties is no longer (as formerly) by the
actual presence in court, either by themselves or their attorneys; but, it
must be remembered, an appearance of this kind is still supposed, and exists
in contemplation of law. The appearance is effected on the part of the
defendant (when be is not arrested) by making certain formal entries in the
proper office of the court, expressing his appearance; 5 Watts & Serg. 215;
1 Scam. R. 250; 2 Seam. R. 462; 6 Port. R. 352; 9 Port. R. 272; 6 Miss. R.
50; 7 Miss. R. 411; 17 Verm. 531; 2 Pike, R. 26; 6 Ala. R. 784; 3 Watts &
Serg. 501; 8 Port. R. 442; or, in case of arrest, it may be considered as
effected by giving bail to the action. On the part of the plaintiff no
formality expressive of appearance is observed.
     4. In general, the appearance of either party may be in person or by
attorney, and, when by attorney, there is always supposed to be a warrant of
attorney executed to the attorney by his client, authorizing such
appearance.
     5. But to this general rule there are various exceptions; persons
devoid of understanding, as idiots, and persons having understanding, if
they are by law deprived of a capacity to appoint an attorney, as married
women, must appear in person. The appearance of such persons must purport,
and is so entered on the record, to be in person, whether in fact an
attorney be employed or not. See Tidd's Pr. 68, 75; 1 Arch. Pract. 22; 2
John. 192; 8 John. 418; 14 John. 417; 5 Pick. 413; Bouv. Inst. Index, h.t.
     6. There must be an appearance in person in the following cases: 1st.
An idiot can appear only in person, and as, a plaintiff he may sue in person
or by his next friend 2d. A married woman, when sued without her husband,
should defend in person 3 Wms. Saund. 209, b and when the cause of action
accrued before her marriage, and she is afterwards sued alone, she must
plead her coverture in person, and not by attorney. Co. Litt. 125. 3d. When
the party pleads to the jurisdiction, be must plead in person. Summ.on Pl.
51; Merrif. Law of Att. 58. 4th. A plea of misnomer must always be in
person, unless it be by special warrant of attorney. 1 Chit. Pl. 398; Summ.
on Pl. 50; 3 Wms. Saund. 209 b.
     7. An infant cannot appoint an attorney; he must therefore prosecute or
appear by guardian, or prochein ami.
     8. A lunatic, if of full age, may appear by. attorney; if, under age,
by guardian. 2 Wms. Saund. 335; Id. 332 (a) n. (4.)
     9. When an appearance is lawfully entered by the defendant, both
parties are considered as being in court. Imp. Pr. 215. And if the defendant
pleads to issue, defects of process are cured but not, if he demurs to the
process, (I Lord Raym. 21,) or, according to the practice of some courts,
appears de bene esse, or otherwise conditionally.
    10. In criminal cases, the personal presence of the accused is often
necessary. It has been held, that if the record of a conviction of a
misdemeanor be removed by certiorari, the personal presence of the defendant
is necessary, in order to move in arrest. of judgment: but, after a special
verdict, it is not necessary that the defendant should be personally present
at the argument of it. 2 Burr. 931 1 Bl. Rep. 209, S. C. So, the defendant
must appear personally in court, when an order of bastardy is quashed and
the reason is, he must enter into a recognizance to abide the order of
sessions below. 1 Bl. Rep. 198. So, in a case, when two justices of the
peace, having confessed an information for misbehavior in the execution of
their office, and a motion was made to dispense with their personal
appearance, on their clerks undertaking in court to answer for their flues,
the court declared the rule to be, that although such a motion was subject
to the discretion of the court either to grant or refuse it, in cases where
it is clear that the punishment would not be corporal, yet it ought to be
denied in every case where it is either probable or possible that the
punishment would be corporal; and therefore the motion was overruled in that
case. And Wilmot and Ashton, Justices, thought, that even where the
punishment would most probably be pecuniary only, yet in offences of a very
gross and public nature, the persons convicted should appear in person, for
the sake of example and prevention of the like offences being committed by
other persons; as the notoriety of being called up to answer criminally for
such offences, would very much conduce to deter others from venturing to
commit the like. 3 Burr. 1786, 7.