challenge on

challenge (one) on (something)

To question one, perhaps aggressively, on a particular issue, statement, or viewpoint. I had to challenge him on that remark about sales because the budget report did not support it at all. That is a positively absurd statement, and I'm glad someone challenged her on it. Challenging someone on their political beliefs the first time you meet them is usually not the best idea.See also: challenge, on

challenge someone on something

to dispute someone's statement, remarks, or position. I think Fred is wrong, but I won't challenge him on his estimate.See also: challenge, on