The Collaborative International Dictionary of English v.0.48:

Harmonic \Har*mon"ic\ (h[aum]r*m[o^]n"[i^]k), Harmonical
\Har*mon"ic*al\ (-[i^]*kal), a. [L. harmonicus, Gr. "armoniko`s;
   cf. F. harmonique. See Harmony.]
   1. Concordant; musical; consonant; as, harmonic sounds.
      [1913 Webster]

            Harmonic twang! of leather, horn, and brass. --Pope.
      [1913 Webster]

   2. (Mus.) Relating to harmony, -- as melodic relates to
      melody; harmonious; esp., relating to the accessory sounds
      or overtones which accompany the predominant and apparent
      single tone of any string or sonorous body.
      [1913 Webster]

   3. (Math.) Having relations or properties bearing some
      resemblance to those of musical consonances; -- said of
      certain numbers, ratios, proportions, points, lines,
      motions, and the like.
      [1913 Webster]

   Harmonic interval (Mus.), the distance between two notes of
      a chord, or two consonant notes.

   Harmonical mean (Arith. & Alg.), certain relations of
      numbers and quantities, which bear an analogy to musical
      consonances.

   Harmonic motion, the motion of the point A, of the foot of
      the perpendicular PA, when P moves uniformly in the
      circumference of a circle, and PA is drawn perpendicularly
      upon a fixed diameter of the circle. This is simple
      harmonic motion. The combinations, in any way, of two or
      more simple harmonic motions, make other kinds of harmonic
      motion. The motion of the pendulum bob of a clock is
      approximately simple harmonic motion.

   Harmonic proportion. See under Proportion.

   Harmonic series or Harmonic progression. See under
      Progression.

   Spherical harmonic analysis, a mathematical method,
      sometimes referred to as that of Laplace's Coefficients,
      which has for its object the expression of an arbitrary,
      periodic function of two independent variables, in the
      proper form for a large class of physical problems,
      involving arbitrary data, over a spherical surface, and
      the deduction of solutions for every point of space. The
      functions employed in this method are called spherical
      harmonic functions. --Thomson & Tait.

   Harmonic suture (Anat.), an articulation by simple
      apposition of comparatively smooth surfaces or edges, as
      between the two superior maxillary bones in man; -- called
      also harmonia, and harmony.

   Harmonic triad (Mus.), the chord of a note with its third
      and fifth; the common chord.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Harmony \Har"mo*ny\ (h[aum]r"m[-o]*n[y^]), n.; pl. Harmonies
   (-n[i^]z). [F. harmonie, L. harmonia, Gr. "armoni`a joint,
   proportion, concord, fr. "armo`s a fitting or joining. See
   Article.]
   1. The just adaptation of parts to each other, in any system
      or combination of things, or in things intended to form a
      connected whole; such an agreement between the different
      parts of a design or composition as to produce unity of
      effect; as, the harmony of the universe.
      [1913 Webster]

   2. Concord or agreement in facts, opinions, manners,
      interests, etc.; good correspondence; peace and
      friendship; as, good citizens live in harmony.
      [1913 Webster]

   3. A literary work which brings together or arranges
      systematically parallel passages of historians respecting
      the same events, and shows their agreement or consistency;
      as, a harmony of the Gospels.
      [1913 Webster]

   4. (Mus.)
      (a) A succession of chords according to the rules of
          progression and modulation.
      (b) The science which treats of their construction and
          progression.
          [1913 Webster]

                Ten thousand harps, that tuned
                Angelic harmonies.                --Milton.
          [1913 Webster]

   5. (Anat.) See Harmonic suture, under Harmonic.
      [1913 Webster]

   Close harmony, Dispersed harmony, etc. See under Close,
      Dispersed, etc.

   Harmony of the spheres. See Music of the spheres, under
      Music.

   Syn: Harmony, Melody.

   Usage: Harmony results from the concord of two or more
          strains or sounds which differ in pitch and quality.
          Melody denotes the pleasing alternation and variety of
          musical and measured sounds, as they succeed each
          other in a single verse or strain.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Thorough bass \Thor"ough bass`\ (Mus.)
   The representation of chords by figures placed under the
   base; figured bass; basso continuo; -- sometimes used as
   synonymous with harmony.
   [1913 Webster]

WordNet (r) 3.0 (2006):

harmony
    n 1: compatibility in opinion and action [syn: harmony,
         harmoniousness]
    2: the structure of music with respect to the composition and
       progression of chords [syn: harmony, musical harmony]
    3: a harmonious state of things in general and of their
       properties (as of colors and sounds); congruity of parts with
       one another and with the whole [syn: harmony, concord,
       concordance]
    4: agreement of opinions [syn: harmony, concord,
       concordance]
    5: an agreeable sound property [ant: dissonance]

Moby Thesaurus II by Grady Ward, 1.0:

292 Moby Thesaurus words for "harmony":
   acclamation, accommodation, accord, accordance, acquiescence,
   adaptation, adaption, adjustment, affinity, agape, agreement,
   agreement of all, amity, an in, arrangement, array, articulation,
   assent, atlas, attune, attunement, balance, beauty,
   bilateral symmetry, bipartisanship, bliss, bonds of harmony,
   brotherly love, calendar, caritas, casebook, catalog,
   catalogue raisonne, cement of friendship, cessation of combat,
   charity, chime, chiming, chorus, city directory,
   classified catalog, closeness, coaction, coadjuvancy,
   coadministration, coagency, coaptation, cochairmanship,
   codirectorship, coherence, coincidence, collaboration,
   collaborativeness, collectivism, collusion, commensalism,
   common assent, common consent, common effort, common enterprise,
   communalism, communion, communism, communitarianism, community,
   community of interests, compatibility, compliance, complicity,
   concatenation, concentus, concert, concinnity, concord,
   concordance, concurrence, conformance, conformation,
   conformation other-direction, conformity, congeniality, congruence,
   congruency, congruity, consensus, consensus gentium,
   consensus of opinion, consensus omnium, consent, consentaneity,
   consistency, consonance, consonancy, consort, conventionality,
   cooperation, cooperativeness, correspondence, cyclopedia,
   deployment, diapason, diatesseron, dictionary catalog, dignity,
   directory, disposal, disposition, duet, duumvirate,
   dynamic symmetry, ecumenicalism, ecumenicism, ecumenism, elegance,
   empathy, encyclopedia, equality, equilibrium, equivalence, esprit,
   esprit de corps, euphony, eurythmics, eurythmy, evenness,
   exemption from hostilities, favor, favorable regard,
   feeling of identity, fellow feeling, fellowship, finish, fitness,
   flexibility, formation, freedom from war, frictionlessness,
   friendly relations, gazetteer, general acclamation,
   general agreement, general consent, general voice, good graces,
   good terms, good understanding, good vibes, good vibrations,
   goodwill, grace, happy family, harmonics, heavy harmony, homophony,
   identity, index, integration, integrity, intersection,
   joining of forces, joint effort, joint operation, keeping, kinship,
   layout, liberty in tranquillity, like-mindedness, line, lineup,
   love, malleability, marshaling, mass action, measure, measuredness,
   meeting of minds, mellifluousness, melodics, melodiousness, melody,
   monochord, monody, morale, multilateral symmetry, music,
   music theory, musicality, musicography, musicology,
   mutual assistance, mutual regard, mutual understanding, mutualism,
   mutuality, obedience, observance, octet, one accord, one voice,
   oneness, order, orderedness, orderliness, organization, orthodoxy,
   overlap, parallelism, pax, peace, peacetime, phone book, pliancy,
   polyglot, polyphony, pooling, pooling of resources, proportion,
   proportionality, pulling together, quartet, quiet, quietude,
   quintet, rapport, rapprochement, reciprocity, reconcilement,
   reconciliation, record book, reference book, regard, regularity,
   respect, rhythm, rhythmics, routine, same mind, self-consistency,
   septet, setup, sextet, shapeliness, sharing, single voice,
   solidarity, sonority, source book, spirituality, strictness,
   structure, studbook, sweetness, symbiosis, symmetricalness,
   symmetry, sympathy, symphony, sync, synchronism, synchronization,
   synergism, synergy, system, tally, team spirit, teamwork,
   telephone book, telephone directory, theory, three-part harmony,
   timing, togetherness, total agreement, traditionalism,
   tranquillity, trilateral symmetry, trio, triumvirate, troika, tune,
   tunefulness, unanimity, unanimousness, understanding, uniformity,
   union, unison, unisonance, united action, unity,
   universal agreement, work of reference



U.S. Gazetteer Places (2000):

Harmony, NC -- U.S. town in North Carolina
   Population (2000):    526
   Housing Units (2000): 223
   Land area (2000):     1.382112 sq. miles (3.579653 sq. km)
   Water area (2000):    0.003144 sq. miles (0.008142 sq. km)
   Total area (2000):    1.385256 sq. miles (3.587795 sq. km)
   FIPS code:            29640
   Located within:       North Carolina (NC), FIPS 37
   Location:             35.961588 N, 80.773947 W
   ZIP Codes (1990):     28634
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Harmony, NC
    Harmony


U.S. Gazetteer Places (2000):

Harmony, IN -- U.S. town in Indiana
   Population (2000):    589
   Housing Units (2000): 255
   Land area (2000):     0.754158 sq. miles (1.953259 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.754158 sq. miles (1.953259 sq. km)
   FIPS code:            31486
   Located within:       Indiana (IN), FIPS 18
   Location:             39.535401 N, 87.073872 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Harmony, IN
    Harmony


U.S. Gazetteer Places (2000):

Harmony, PA -- U.S. borough in Pennsylvania
   Population (2000):    937
   Housing Units (2000): 434
   Land area (2000):     0.379664 sq. miles (0.983324 sq. km)
   Water area (2000):    0.004846 sq. miles (0.012552 sq. km)
   Total area (2000):    0.384510 sq. miles (0.995876 sq. km)
   FIPS code:            32688
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             40.801452 N, 80.127412 W
   ZIP Codes (1990):     16037
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Harmony, PA
    Harmony


U.S. Gazetteer Places (2000):

Harmony, MN -- U.S. city in Minnesota
   Population (2000):    1080
   Housing Units (2000): 500
   Land area (2000):     1.138171 sq. miles (2.947848 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.138171 sq. miles (2.947848 sq. km)
   FIPS code:            27188
   Located within:       Minnesota (MN), FIPS 27
   Location:             43.552703 N, 92.009421 W
   ZIP Codes (1990):     55939
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Harmony, MN
    Harmony