From Longman Dictionary of Contemporary Englishdeciderde‧cid‧er /dɪˈsaɪdə $ -ər/ noun [countable usually singular] DSDECIDEthe last part of a game or competition, which will show who the winner is This next round will be the decider.
Examples from the Corpus
decider• But if nothing else, the McKenna decider served one purpose - it helped to put additional fire in Derry's bellies.• Easter sees the potential decider at St. Helen's between Swansea and Llanelli.• There is a lot of work that has to be done by the decider in order to bridge the gap.• In both cases the decider ends up where he started from.• But Davis won the eighth frame and then compiled a break of 50 in the decider.• But he couldn't quite repeat the performance against Parrot, recovering from 5-2 down to 5-all before losing the decider.• But in 1987 Derry beat Armagh in the Ulster decider with McGurk being pressed into action during the game.