Definition of swingiest:
(adj) :
(informal) Having a swinging motion.
(adj) :
(informal) Characteristic of swing music.
(adj) :
(informal, politics) Having many swing voters.
(adj) :
Variable in mood; liable to having mood swings.
(adj) :
(sports, games) Inconsistent in performance.
(adj) :
(curling, of ice) Allowing stones to curl more than usual.