open and shut

Clear-cut or straightforward, as of a legal case. Often hyphenated if used before a noun. With all the evidence against the defendant, I expect this to be an open-and-shut case. Her signature on the documents proves she accepted the payment, so it seems pretty open and shut who is responsible.

Simple, straightforward, easily solved, as in With three eyewitnesses, the prosecutor said this case was open and shut. This term suggests that one has immediate access to the facts of a situation. [c. 1840]

If something, especially a legal case, is open and shut, it is easily decided or solved because the facts are very clear. We'll need to come back here and measure things for the report, but it seems open and shut to me. Note: Open-and-shut is often used before nouns. The prosecution behaved as if they had an open-and-shut case. Note: In this expression, the word `and' means `and then', suggesting that the case being dealt with has been opened and then closed again almost immediately because it was easy to solve or deal with.