cliffhangernoun [ C ]
uk/ˈklɪfˌhæŋ.ər/us/ˈklɪfˌhæŋ.ɚ/a story or a situation that is exciting because its ending or result is uncertain until it happens:
Many of Hitchcock's films are real cliffhangers.
It looks as if the election is going to be a cliffhanger.