guarantee
noun
a promise or assurance, especially one in writing, that something is of specified quality, content, benefit, etc., or that it will perform satisfactorily for a given length of time.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That flex began in the middle of the week, when Dallas Coach Mike McCarthy kinda-sorta quasi-guaranteed a win.
From Washington Post ● Dec. 12, 2021