noun Date: 1867 a periodic motion (as of a sounding violin string or swinging pendulum) that has a single frequency or amplitude or is composed of two or more such simple periodic motions
HARMONIC MOTION
Meaning of HARMONIC MOTION in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012