means A repeated back-and-forth movement between two points or states, like a pendulum swinging or a value rising and falling around a center.

from From Latin 'oscillare,' to swing, which traces back to 'oscillum' — a little face or mask of Bacchus that Roman farmers hung from trees in vineyards, letting it sway in the breeze as a charm for fertile soil. So the word for swinging began, charmingly, as a tiny swinging god.