A witness in the case, perhaps your fiancee, has a prior record. Whoever filed the motion wants the other side to be prohibited from attacking the witness's credibility by asking about his prior record. In other words, one side does not want the other side to tell the jury at trial that a witness has a prior record. The rules of evidence govern when the opposing party can attack a witness with his prior convictions. Here, someone wants the judge to rule that the opposing party cannot use the prior record of the witness.
This answer is provided for educational purposes only and is not intended as the practice of law in any jurisdiction in which I am not licensed. The answer does not constitute legal advice nor does it create an attorney-client relationship. The answer is based only on the information provided, and may be inaccurate in the context of additional facts that have not been provided. The questioner should be aware that I am only licensed to practice law in the state and federal courts of Minnesota. Accordingly, before taking any action or refraining from taking any action, the questioner should consult with an attorney licensed to practice in his or her jurisdiction.