\Har*mon"ic\, Harmonical \Har*mon"ic*al\, a. [L.
harmonicus, Gr. ?; cf. F. harmonique. See {Harmony}.]
1. Concordant; musical; consonant; as, harmonic sounds.
         Harmonic twang! of leather, horn, and brass. --Pope.
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.
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.
{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},

\Har*mon"ic\, n. (Mus.)
A musical note produced by a number of vibrations which is a
multiple of the number producing some other; an overtone. See
{Harmonics}.