Swing  —v. (past and past part. Swung) 1 a (cause to) move with a to-and-fro or curving motion, as of an object attached at one end and hanging free at the other; sway. B hang so as to be free to swing. 2 oscillate or revolve. 3 move by gripping something and leaping etc. (swung from tree to tree). 4 walk with a swing. 5 (foll. By round) move to face the opposite direction. 6 change one's opinion or mood. 7 (foll. By at) attempt to hit. 8  (also swing it) play (music) with a swing rhythm. 9 colloq. (of a party etc.) Be lively etc. 10 have a decisive influence on (voting etc.). 11 colloq. Achieve, manage. 12 colloq. Be executed by hanging. —n. 1 act, motion, or extent of swinging. 2 swinging or smooth gait, rhythm, or action. 3 a seat slung by ropes etc. For swinging on or in. B period of swinging on this. 4 a jazz or dance music with an easy flowing rhythm. B rhythmic feeling or drive of this. 5 discernible change, esp. In votes or points scored etc.  swings and roundabouts situation affording equal gain and loss.  swinger n. [old english]