oscillate
UK: ˈɒsɪleɪt | US: ˈɑːsɪleɪt
vi. to move or swing back and forth in a regular rhythm
vi. to waver between differing opinions, states, or actions
vt. to cause to move back and forth
The word oscillate traces back to the Latin oscillum, a diminutive of os (mouth), referring to small masks of Bacchus hung in vineyards. These masks swung in the wind, symbolizing movement. Over time, oscillum evolved to denote any swinging motion, and the verb oscillate emerged in English (17th century) to describe rhythmic back-and-forth movement or indecision.
The pendulum began to oscillate steadily after being released.
Her mood tends to oscillate between excitement and anxiety.
The fan oscillates to distribute air evenly across the room.
Economists observed the currency's value oscillate wildly during the crisis.
He oscillated for weeks before choosing a university.