noun

"Assurance" has several meanings in English, but the most common ones are:
Guarantee or promise: This is the most common meaning of "assurance". It refers to a statement that something will be done or that something is true. For example, you might say "The insurance company gave me an assurance that my claim would be processed quickly" or "The teacher gave her students assurance that they would all pass the exam."

Example

1. I have the assurance that everything will turn out alright.
2. My boss gave me an assurance that I would be promoted next year.
3. She gave me her assurance that she would keep my secret.