According to the Wisconsin Department of Corrections, "sentence imposed and stayed" means that the court has sentenced someone to jail, but has stayed, meaning delayed, the execution of the sentence. In many cases, this occurs pending an appeal or when the court decides to give probation instead of jail time.
The wording of "sentence imposed and stayed" in criminal proceedings varies slightly by state. This specific term is used commonly in Wisconsin criminal proceedings and is more often than not used to give a defendant probation. If the defendant violates the terms of probation, it gets revoked and the original jail sentence is imposed.