The Collaborative International Dictionary of English v.0.48:

Fluster \Flus"ter\, v. t. [imp. & p. p. Flustered; p. pr. &
   vb. n. Flustering.] [Cf. Icel. flaustra to be flustered,
   flaustr a fluster.]
   To make hot and rosy, as with drinking; to heat; hence, to
   throw into agitation and confusion; to confuse; to muddle.
   [1913 Webster]

         His habit or flustering himself daily with claret.
                                                  --Macaulay.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Fluster \Flus"ter\, v. i.
   To be in a heat or bustle; to be agitated and confused.
   [1913 Webster]

         The flstering, vainglorious Greeks.      --South.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Fluster \Flus"ter\, n.
   Heat or glow, as from drinking; agitation mingled with
   confusion; disorder.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fluster
    n 1: a disposition that is confused or nervous and upset [syn:
         perturbation, fluster]
    v 1: be flustered; behave in a confused manner
    2: cause to be nervous or upset

Moby Thesaurus II by Grady Ward, 1.0:

191 Moby Thesaurus words for "fluster":
   addle, addle the wits, ado, agitate, agitation, baffle, bafflement,
   ball up, becloud, bedazzle, befuddle, befuddlement, bewilder,
   bewilderment, bluff, bluster, bluster and bluff, blustering,
   boastfulness, bobbery, boil, boiling, bother, botheration, bravado,
   brouhaha, bug, bullying, burst, bustle, chaos, churn, cloud,
   commotion, confound, confuse, confusion, conturbation, daze,
   dazzle, discombobulate, discombobulation, discomfit, discomfiture,
   discomfort, discommode, discompose, discomposure, disconcert,
   disconcertion, disorder, disorganization, disorganize, disorient,
   disorientation, disquiet, disquietude, distract, distraction,
   disturb, disturbance, dither, dizzy, ebullition, electrify,
   embarrass, embarrassment, embroilment, entangle, excitement,
   fanfaronade, faze, feery-fary, ferment, fermentation, fever,
   feverishness, fidgetiness, fidgets, fit, flap, flummox, flurry,
   flusteration, flustration, flutter, flutteration, flutteriness,
   fog, foment, foofaraw, frenzy, fret, fuddle, fuddlement, fume,
   fuss, fussiness, hassle, haze, hectoring, hubbub, hullabaloo,
   hurly-burly, inquietude, intimidation, jar, jitters, jolt, jumble,
   jumpiness, lather, maelstrom, malaise, maze, mess, mist, mix up,
   moider, moil, muddle, muddlement, mystify, nerviness, nervosity,
   nervousness, nonplus, perplex, perplexity, perturb, perturbation,
   pother, pucker, put off, put out, puzzle, raise hell, rant, rattle,
   restlessness, rock, rodomontade, roil, rout, row, ruffle, scramble,
   seethe, seething, shake, shake up, shock, shuffle, side, spasm,
   splutter, spurt, sputter, stagger, stew, stir, stir up, swagger,
   swashbucklery, sweat, swirl, swivet, throw, throw into confusion,
   throw off, tizzy, to-do, trepidation, trepidity, trouble, tumult,
   tumultuation, turbidity, turbulence, turmoil, twitter,
   twitteration, unease, unhinge, unquiet, unrest, unsettle,
   unsettlement, upset, vortex, whirl