(1):
(a.) Having relations or properties bearing some resemblance to those of musical consonances; - said of certain numbers, ratios, proportions, points, lines. motions, and the like.
(2):
(a.) Concordant; musical; consonant; as, harmonic sounds.
(3):
(a.) 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.