cast doubt on

cast doubt on (someone or something)

To cause someone or something to be viewed with doubt, skepticism, or uncertainty. I considered Walt for the promotion, but his constant lateness soon cast doubt on that decision. Such a significant error really cast doubt on all of the experiment's results.See also: cast, doubt, on

cast doubt on

Cause something or someone to be questioned. For example, The prosecutor cast doubt on the wife's alibi. This idiom uses cast in the sense of "throw," a usage dating from the early 1200s. See also: cast, doubt, on