certainty
/ˈsɜːtəntɪ/noun
(pl. -ies)［mass noun］
1- firm conviction that something is the case确信, 坚信：
she knew with absolute certainty that they were dead.
她绝对确信他们死了。
1.1
- the quality of being reliably true确实性; 无疑, 肯定：
there is a bewildering lack of certainty and clarity in the law.
法律中存在着令人困惑的不肯定和不清楚的内容。
1.2
- a general air of confidence自信的神态：
a man exuding certainty.
一位显露自信的男子。
1.3
- count noun a fact that is definitely true or an event that is definitely going to take place确定的事实; 必然发生的事：
the passing of the act made a general election a certainty.
法案的通过使大选成为必然。
1.4
- count noun a thing or person that may be relied on in a specified context or to do something specified靠得住的事物（或人）; 被确信能做成某事的人（或物）：
he was expected to be a certainty for a gold medal.
他被认为可稳得金牌。
短语
for a certainty
- beyond the possibility of doubt确定无疑地。
词源
Middle English: from Old French certainete, from certain （see CERTAIN）.