cliff‧hang‧er /ˈklɪfˌhæŋə $ -ər/ noun [countable]
a situation in a story, film, or competition that makes you feel very excited or nervous because you do not know what will happen or have to wait a long time to see how it will end:
Tonight’s vote may be a cliffhanger.
the episode’s cliffhanger ending
—cliffhanging adjective

[TahlilGaran] Dictionary of Contemporary English ▲

cliffhanger
a sports event/movie/election where the outcome is uncertain until the very end
The playoff game was a cliffhanger and the most exciting game of the year.

[TahlilGaran] English Idioms Dictionary ▲

cliffhanger
n., informal A sports event or a movie in which the outcome is uncertain to the very end keeping the spectators in great suspense and excitement.
Did you see "The Fugitive"? It's a regular cliffhanger.

[TahlilGaran] English Idioms Dictionary ▲