The Collaborative International Dictionary of English v.0.48:

Posture \Pos"ture\ (?; 135), n. [F., fr. L. positura, fr.
   ponere, positum, to place. See Position.]
   1. The position of the body; the situation or disposition of
      the several parts of the body with respect to each other,
      or for a particular purpose; especially (Fine Arts), the
      position of a figure with regard to the several principal
      members by which action is expressed; attitude.
      [1913 Webster]

            Atalanta, the posture of whose limbs was so lively
            expressed . . . one would have sworn the very
            picture had run.                      --Sir P.
                                                  Sidney.
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            In most strange postures
            We have seen him set himself.         --Shak.
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            The posture of a poetic figure is a description of
            his heroes in the performance of such or such an
            action.                               --Dryden.
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   2. Place; position; situation. [Obs.] --Milton.
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            His [man's] noblest posture and station in this
            world.                                --Sir M. Hale.
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   3. State or condition, whether of external circumstances, or
      of internal feeling and will; disposition; mood; as, a
      posture of defense; the posture of affairs.
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            The several postures of his devout soul.
                                                  --Atterbury.
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   Syn: Attitude; position. See Attitude.
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The Collaborative International Dictionary of English v.0.48:

Posture \Pos"ture\ (?; 135), v. t. [imp. & p. p. Postured; p.
   pr. & vb. n. Posturing.]
   To place in a particular position or attitude; to dispose the
   parts of, with reference to a particular purpose; as, to
   posture one's self; to posture a model. --Howell.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Posture \Pos"ture\, v. i.
   1. To assume a particular posture or attitude; to contort the
      body into artificial attitudes, as an acrobat or
      contortionist; also, to pose.
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   2. Fig.: To assume a character; as, to posture as a saint.
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WordNet (r) 3.0 (2006):

posture
    n 1: the arrangement of the body and its limbs; "he assumed an
         attitude of surrender" [syn: position, posture,
         attitude]
    2: characteristic way of bearing one's body; "stood with good
       posture" [syn: carriage, bearing, posture]
    3: a rationalized mental attitude [syn: position, stance,
       posture]
    4: capability in terms of personnel and materiel that affect the
       capacity to fight a war; "we faced an army of great
       strength"; "politicians have neglected our military posture"
       [syn: military capability, military strength, strength,
       military posture, posture]
    v 1: behave affectedly or unnaturally in order to impress
         others; "Don't pay any attention to him--he is always
         posing to impress his peers!"; "She postured and made a
         total fool of herself" [syn: pose, posture]
    2: assume a posture as for artistic purposes; "We don't know the
       woman who posed for Leonardo so often" [syn: model, pose,
       sit, posture]

Moby Thesaurus II by Grady Ward, 1.0:

236 Moby Thesaurus words for "posture":
   acting, action, actions, activity, acts, address, affect,
   affectation, affectivity, air, appearance, arrangement, array,
   assumption, attitude, attitudinize, attitudinizing, bearing,
   bearings, beck, beckon, behavior, behavior pattern,
   behavioral norm, behavioral science, bluff, bluffing,
   body language, brow, carriage, case, cast, cast of countenance,
   charade, cheating, chironomy, circumstance, climate of opinion,
   color, coloring, common belief, community sentiment, complexion,
   comportment, conceit, concept, conception, conclusion, condition,
   conduct, consensus gentium, consideration, countenance,
   culture pattern, custom, dactylology, deaf-and-dumb alphabet,
   deception, delusion, demeanor, deportment, disguise, disposition,
   dissemblance, dissembling, dissimulation, doing, doings, dumb show,
   emotion, emotivity, estate, estimate, estimation, ethos, eye,
   facade, face, facial appearance, fakery, faking, false air,
   false front, false show, falsity, favor, feature, features,
   feeling, feeling tone, feigning, feint, fix, folkway, footing,
   format, four-flushing, frame of mind, fraud, front, garb,
   general belief, gesticulation, gesture, gesture language, gestures,
   gilt, gloss, goings-on, guise, hand signal, humbug, humbuggery,
   idea, imposture, impression, jam, judgment, kinesics, layout,
   lights, lineaments, lines, location, looks, lot, maintien, manner,
   manners, masquerade, mental attitude, meretriciousness, method,
   methodology, methods, mien, mind, modality, mode, modus vivendi,
   mood, motion, motions, movement, movements, moves, mystique,
   notion, observable behavior, observation, opinion, organization,
   orientation, ostentation, outlook, outward show, pantomime, pass,
   pass for, pass off, pattern, peacock, personal judgment,
   physiognomy, pickle, place, playacting, plight, point of view,
   poise, popular belief, port, pose, pose for effect, posing,
   position, practice, praxis, predicament, presence, presumption,
   pretense, pretension, pretext, prevailing belief, procedure,
   proceeding, promptness, psychology, public belief, public opinion,
   quickness, rank, reaction, readiness, representation, seeming,
   semblance, sentiment, sham, show, show off, shrug, sight,
   sign language, simulacrum, simulation, sit, situation,
   social science, speciousness, spot, stance, standing, state,
   station, status, strike a pose, strike an attitude, style, tactics,
   theory, thinking, thought, tone, traits, turn, varnish, view,
   viewpoint, visage, way, way of life, way of thinking, ways,
   window dressing