clincher
noun/ˈklɪntʃə(r)/
/ˈklɪntʃər/
[usually singular] (informal)- a fact, a remark or an event that settles an argument, a decision or a competition
- There was a lot of circumstantial evidence but they still needed a clincher, something cast iron that would carry a conviction.
- Mead scored the clincher (= the winning goal) after 81 minutes.
Check pronunciation:
clincher