Formal:
* Abrupt: This is the most direct and literal option, meaning sudden and unexpected.
* Precipitous: This emphasizes the suddenness and steepness of the ending, like falling off a cliff.
* Truncated: This suggests that something has been cut short, like a sentence ending abruptly.
* Curtailed: This implies that the ending was brought to a halt prematurely, often against the will of those involved.
* Ceased: This is a neutral term, simply stating that something has stopped.
Informal:
* Sudden: This is a simple and straightforward word for a sudden ending.
* Sharp: This emphasizes the suddenness and unexpected nature of the ending.
* Cut short: This is a more informal way of saying that something was ended prematurely.
* Stopped dead: This emphasizes the abruptness of the ending, as if something was halted instantly.
Other options:
* Cliffhanger: This suggests an ending that leaves the audience in suspense, wondering what will happen next.
* Anti-climax: This refers to an ending that is disappointing or underwhelming, especially after a buildup of excitement.
The best word to use will depend on the specific situation. For example, if you are writing a formal report, you might use "abrupt" or "truncated". If you are writing a casual conversation, you might use "sudden" or "cut short".