oscillate

verb

Etymology: First attested in 1726; borrowed from Latin ōscillātus, perfect passive participle of Latin ōscillō (“to swing”) (see -ate (verb-forming suffix)), from ōscillum (“a swing”), usually identified with ōscillum (“a little face or mask hung on a tree that sways with the wind”), diminutive of ōs (“mouth, face”). See also osculate.

1. To swing back and forth, especially if with a regular rhythm.

   “A pendulum oscillates slower as it gets longer.”

   “By placing the 0.02μF capacitor on top of the whistle chip, the circuit oscillates at a lower frequency.”

2. To vacillate between conflicting opinions, etc.

   “The mood for change oscillated from day to day.”

3. To vary above and below a mean value.