The Collaborative International Dictionary of English v.0.48:

Arrangement \Ar*range"ment\, n. [Cf. F. arrangement.]
   1. The act of arranging or putting in an orderly condition;
      the state of being arranged or put in order; disposition
      in suitable form.
      [1913 Webster]

   2. The manner or result of arranging; system of parts
      disposed in due order; regular and systematic
      classification; as, arrangement of one's dress; the
      Linn[ae]an arrangement of plants.
      [1913 Webster]

   3. Preparatory proceeding or measure; preparation; as, we
      have made arrangement for receiving company.
      [1913 Webster]

   4. Settlement; adjustment by agreement; as, the parties have
      made an arrangement between themselves concerning their
      disputes; a satisfactory arrangement.
      [1913 Webster]

   5. (Mus.)
      (a) The adaptation of a composition to voices or
          instruments for which it was not originally written.
      (b) A piece so adapted; a transcription; as, a pianoforte
          arrangement of Beethoven's symphonies; an orchestral
          arrangement of a song, an opera, or the like.
          [1913 Webster]

WordNet (r) 3.0 (2006):

arrangement
    n 1: the thing arranged or agreed to; "they made arrangements to
         meet in Chicago" [syn: agreement, arrangement]
    2: an orderly grouping (of things or persons) considered as a
       unit; the result of arranging; "a flower arrangement"
    3: an organized structure for arranging or classifying; "he
       changed the arrangement of the topics"; "the facts were
       familiar but it was in the organization of them that he was
       original"; "he tried to understand their system of
       classification" [syn: arrangement, organization,
       organisation, system]
    4: the spatial property of the way in which something is placed;
       "the arrangement of the furniture"; "the placement of the
       chairs" [syn: placement, arrangement]
    5: a piece of music that has been adapted for performance by a
       particular set of voices or instruments [syn: musical
       arrangement, arrangement]
    6: the act of arranging and adapting a piece of music [syn:
       arrangement, arranging, transcription]

Moby Thesaurus II by Grady Ward, 1.0:

378 Moby Thesaurus words for "arrangement":
   Nachtmusik, abatement of differences, absolute music,
   accommodation, accord, adaptation, adjunct, adjustment, adornment,
   affair, agreement, air varie, aleatory, aleatory music, alignment,
   analysis, anatomy, appointment, approach, architectonics,
   architecture, arrangement, arrangements, array, atmosphere, attack,
   balance, bargain, basic training, binding agreement, blind date,
   blueprint, blueprinting, bond, briefing, brushwork, build,
   building, calculation, canon form, cartel, cataloging,
   categorization, chamber music, chamber orchestra, charting,
   classification, clearing the decks, closing, codification,
   collective agreement, color, color patterns, combination, compact,
   composition, composition of differences, compromise, conception,
   concession, conclusion, concord, conformation, consortium,
   constitution, construction, contract, contract by deed,
   contract of record, contract quasi, contrivance, convention,
   cop-out, copy, covenant, covenant of indemnity, covenant of salt,
   creation, date, deal, debenture, debenture bond, decor, decoration,
   deed, deed of trust, deed poll, deployment, descant,
   desertion of principle, design, device, dicker, display, disposal,
   disposition, distribution, division, double date, draft,
   draftsmanship, edition, elaboration, electronic music,
   embellishment, emblazonment, emblazonry, embroidery,
   employment contract, engagement, engagement book, enterprise,
   envisagement, equipment, etude, evasion of responsibility,
   exercise, fabric, fabrication, familiarization, fashion,
   fashioning, figuring, filing, fixing, flourish, flower arrangement,
   foresight, forethought, forging, form, formal agreement,
   formal contract, format, formation, foundation, frame, fugue form,
   furniture arrangement, game, garnish, garnishment, garniture,
   getup, give-and-take, giving way, grading, graphing, ground plan,
   groundwork, group policy, grouping, guidelines, harmonization,
   harmony, hymnal, hymnbook, idea, illumination, implied contract,
   incidental music, indent, indenture, indexing, instrumental music,
   instrumental score, instrumentation, insurance policy, intention,
   interpretation, interview, intonation, invention,
   ironclad agreement, layout, legal agreement, legal contract,
   libretto, lied form, line, lineup, long-range plan, lute tablature,
   make, makeready, makeup, making, making ready, manufacture,
   mapping, marshaling, master plan, method, methodology,
   mobilization, model, modulation, mold, molding, mortgage deed,
   music, music paper, music roll, musical notation, musical score,
   mutual agreement, mutual concession, nocturne, notation, opera,
   opera score, operations research, opus, orchestral score,
   orchestration, order, ordering, organic structure, organism,
   organization, ornament, ornamentation, pact, paction,
   painterliness, parol contract, part, pattern, patterning, peace,
   perspective, phrasing, physique, piano score, piece, pigeonholing,
   placement, plan, planning, planning function, plans, policy,
   prearrangement, preliminaries, preliminary, preliminary act,
   preliminary step, prep, preparation, preparing, prepping,
   prerequisite, pretreatment, primary form, procedure, processing,
   production, program, program music, program of action, promise,
   promissory note, propaedeutic, proportion, protocol, provision,
   quiet, quietude, ranging, ranking, rating, rationalization,
   readying, recognizance, regularity, resolution, ricercar,
   rondo form, routine, schedule, schema, schematism, schematization,
   scheme, scheme of arrangement, score, sealing, sequence, set-up,
   setting, settlement, setup, shading, shadow, shape, shaping,
   sheet music, short score, signature, signing, solemnization,
   solution, sonata, sonata allegro, sonata form, sonatina, songbook,
   songster, sorting, spadework, special contract, specialty,
   specialty contract, stipulation, strategic plan, strategy,
   stratification, string orchestra, string quartet, structure,
   structuring, study, subdivision, surrender, suspension, symmetry,
   symphonic form, system, systematization, tablature, tabulation,
   tactical plan, tactics, taxonomy, technique, tectonics, terms,
   text, texture, the big picture, the picture, theme and variations,
   tissue, title deed, toccata form, tone, tone painting, training,
   tranquillity, transaction, transcript, transcription, treatment,
   trial, trim, trimming, trio, tryout, typology, understanding,
   uniformity, union contract, valid contract, values, variation,
   version, vocal score, wage contract, warm-up, warp and woof, way,
   weave, web, window dressing, work, working plan, written music,
   yielding