know for a fact(redirected from knows for a fact)
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Related to knows for a fact: known fact
know for a fact
To have definitive knowledge of something. I know for a fact that he cheats in cards! I saw the ace up his sleeve. My mom says she knows for a fact that I'm getting the internship at her company, but I won't believe it until the recruiter calls me.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.