oscillate

“I’m oscillating between thoughtful, anxious, and desperate,” she said.

Since her death, Moynehan’s grief has oscillated among sorrow, fear and anger.

This doesn't mean their spin is completely fixed, however, and all tidally locked moons oscillate back and forth as they orbit.

In a cavity’s lowest mode, the radio waves’ electric field oscillates uniformly up and down along the cavity axis.

Hurricane Milton is currently expected to impact Florida on Wednesday, although experts acknowledge that its oscillating speeds make this somewhat uncertain.