The ending surprised her completely.
Meaning: This means that she was very surprised by the way the story ended.
Choice of Words: Surprised means to cause someone to feel astonishment or wonder. Completely means entirely or totally. Ending is the final part of a story or event. When you put them together, "The ending surprised her completely" means that the final part of the story caused her to feel astonishment or wonder in a total or entire way.
Alternative Expressions
Related Expressions