certainty
/ˈsɜ:tntɪ; `sətntɪ/ n
1 [C] thing that is certain 确定的事情
England will lose the match that's a certainty! 这场比赛英格兰要输--这是肯定的!
That horse is a certainty, ie is certain to win. 那匹马赢定了（准赢）.
2 [U] state of being certain 确知; 确信; 确实; 必然
I can't say with any certainty where I shall be next week. 我说不准我下星期在什麽地方.
We can have no certainty of success. 我们没有成功的把握.