it won't wash(redirected from it will not wash)
it won't wash
Something will not be accepted or believed as true. That kind of excuse may have worked in high school, but it won't wash with me. The deadline for the paper is tomorrow, no extensions. He may be able to skirt the issue in some regions, but it won't wash in these parts—these people want straight answers.
See also: wash
It won't wash!
Fig. Nobody will believe it! Sorry, it won't wash. Try another approach. Don't expect me to believe that! It won't wash.