1. a story, movie, or television episode that ends at a moment of suspense, leaving the audience eager to know what happens next
2. a contest or situation whose outcome remains uncertain until the very end

Examples

• The season finale ended on a cliffhanger with the main character in danger.
• Each episode of the serial was a cliffhanger that kept viewers coming back.
• The election turned into a real cliffhanger with votes being counted late into the night.
• The mystery novel was full of cliffhangers that made it impossible to put down.
• The championship game was a cliffhanger decided by a single point.
• The TV show’s cliffhanger left fans speculating all summer about what would happen next.