certitude
/ˈsɜːtɪtjuːd/noun
mass noun
1- absolute certainty or conviction that something is the case确信, 确定无疑：
the question may never be answered with certitude.
这个问题决不会得到确定无疑的回答。
1.1
- count noun something that someone firmly believes is true深信不疑的事, 确定的事。
词源
late Middle English: from late Latin certitudo, from certus 'certain'.