What is Harmonic?

Harmonic definition and meaning on Dictionary terms:
pertaining to harmony, as distinguished from melody and rhythm.
marked by harmony; in harmony; concordant; consonant.
Physics. of, relating to, or noting a series of oscillations in which each oscillation has a frequency that is an integral multiple of the same basic frequency.
Mathematics. (of a set of values) related in a manner analogous to the frequencies of tones that are consonant. capable of being represented by sine and cosine functions. (of a function) satisfying the Laplace equation.

Music. overtone(def 1).
Physics. a single oscillation whose frequency is an integral multiple of the fundamental frequency.


reference: https://www.dictionary.com/browse/harmonic