A decree nisi is a court order that does not have any force until such time that a particular condition is met, such as a subsequent petition to the court or the passage of a specified period of time.
Once the condition is met, the ruling becomes decree absolute and is binding. Typically, the condition is that no new evidence or further petitions with a bearing on the case are introduced to the court. The wording of such a decree is generally in the form of "that the marriage, had and solemnized on (date) between AB and CD, be dissolved by reason that (grounds) UNLESS sufficient cause be shown to the court why this decree should not be made absolute within six weeks of the making hereof". This allows time for any party who objects to the divorce to come forward with those objections. It is also at times termed as a rule nisi.