10. Swing, sway, oscillate, rock suggest a movement back and forth. Swing expresses the comparatively regular motion to and fro of a body supported from the end or ends, especially from above: A lamp swings from the ceiling. To sway is to swing gently and is used especially of fixed objects or of persons: Young oaks sway in the breeze. Oscillate refers to the smooth, regular, alternating movement of a body within certain limits between two fixed points. Rock indicates the slow and regular movement back and forth of a body, as on curved supports: A cradle rocks. 21. sway, vibration, oscillation. 22. range, scope, sweep, play.