oscillate

Meanings

1. To swing back and forth, especially if with a regular rhythm.
2. To vacillate between conflicting opinions, etc.
3. To vary above and below a mean value.

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.