The Collaborative International Dictionary of English v.0.48:

Discomposure \Dis`com*po"sure\ (?; 135), n.
   1. The state of being discomposed; disturbance; disorder;
      agitation; perturbation.
      [1913 Webster]

            No discomposure stirred her features. --Akenside.
      [1913 Webster]

   2. Discordance; disagreement of parts. [Obs.] --Boyle.
      [1913 Webster]

WordNet (r) 3.0 (2006):

discomposure
    n 1: anxious embarrassment [syn: discomfiture, discomposure,
         disconcertion, disconcertment]
    2: a temperament that is perturbed and lacking in composure
       [ant: calm, calmness, composure, equanimity]

Moby Thesaurus II by Grady Ward, 1.0:

190 Moby Thesaurus words for "discomposure":
   abashment, agitation, angst, anguish, anxiety, baffle, bafflement,
   befuddlement, bewilderment, bluster, bobbery, boil, boiling,
   boredom, bother, botheration, brouhaha, bustle, chagrin, chaos,
   cheerlessness, churn, cloud, commotion, confoundment, confusion,
   conturbation, convulsion, daze, derangement, dilemma,
   disarrangement, disarray, disarticulation, discombobulation,
   discomfiture, discomfort, disconcert, disconcertedness,
   disconcertion, disconcertment, discontent, discountenance,
   disharmony, dishevelment, disintegration, disjunction, dislike,
   dislocation, disorder, disorderliness, disorganization,
   disorientation, displeasure, disproportion, disquiet, disquietude,
   disruption, dissatisfaction, distress, disturbance, dread,
   dullness, ebullition, embarrassment, embroilment, emptiness,
   enigma, ennui, entropy, excitement, existential woe, ferment,
   fermentation, fever, feverishness, fidgets, fix, flap, flatness,
   flummox, flurry, fluster, flutter, flutteration, fog, foment,
   frenzy, fuddle, fuddlement, fume, fuss, grimness, haphazardness,
   haze, hubbub, hurly-burly, incoherence, indiscriminateness,
   inharmonious harmony, inquietude, insanity, irregularity, jam,
   jitters, joylessness, jumble, jumpiness, lack of pleasure,
   maelstrom, malaise, maze, mess, misarrangement, mist, moil,
   mortification, most admired disorder, muddle, muddlement, mystery,
   nausea, nerviness, nervosity, nervousness, nongratification,
   nonplus, nonsatisfaction, nonsymmetry, nonuniformity, painfulness,
   perplexity, perturbation, pickle, plight, pother, predicament,
   problem, promiscuity, promiscuousness, pucker, puzzle, puzzlement,
   quandary, randomness, restlessness, riddle, roil, rout, row,
   ruffle, savorlessness, scrape, seethe, seething, shuffle,
   shuffling, spleen, staleness, stew, stir, sweat, swirl, swivet,
   tastelessness, tediousness, tedium, tizzy, to-do, trepidation,
   trepidity, tumult, tumultuation, turbidity, turbulence, turmoil,
   twitter, unassuredness, uncomfortableness, unease, uneasiness,
   unhappiness, unpleasure, unrest, unsatisfaction, unsettlement,
   unsymmetry, ununiformity, upset, vexation of spirit