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
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.
2. Concord or agreement in facts, opinions, manners,
interests, etc.; good correspondence; peace and
friendship; as, good citizens live in harmony.
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.
(a) A succession of chords according to the rules of
progression and modulation.
(b) The science which treats of their construction and
Ten thousand harps, that tuned
Angelic harmonies. --Milton.
5. (Anat.) See Harmonic suture, under Harmonic.
Close harmony, Dispersed harmony, etc. See under Close,
Harmony of the spheres. See Music of the spheres, under
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.