oscillate

A tiny Roman charm may be hiding inside this word. In Latin, an ōscillum was a little face or mask hung up on a tree or porch, something that literally swayed when the wind caught it, and that wobbling image eventually gave rise to ōscillāre, “to swing.” English picked up the verb in 1726, and by the 20th century physicists were using it for electric currents that rise and fall the way a pendulum does. The family resemblance is delightfully odd: oscillate shares a theatrical ancestor with osculate, the kissing word, because both reach back to Latin ōs, “mouth” or “face.” So when a politician oscillates between positions, picture not a grand philosophy seminar but a little mask nodding in the breeze — a face that can never quite keep still.