## harmonic

- Any integral multiple of the lowest (or fundamental) frequency of a physical system.

For example, the motion of a taut, gently plucked violin string is the superposition of sinusoidal motions with frequencies ω_{0}, ω_{1}= 2ω_{0}, ω_{2}, 3ω_{0}, . . . where ω_{0}is the fundamental frequency and ω_{1}, ω_{2}, . . . are the harmonics (or overtones), resulting in a harmonious composite sound.

- A sine or cosine component of the Fourier series representation of an empirical or theoretical function.