1) Divorce document 2) Latin legal terminology 
A decree nisi ({ety|la|nisi|unless}) 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 evidenc...
(from the article `interlocutory decree`) ...a judicial decision that is not final or that deals with a point other than the principal subject matter of the controversy at hand. An ...
The step before declaring a Decree Absolute. The Decree Absolute is usually made six weeks later. In theory the time between the nisi and the absolute is so that another party can take action to prevent the decree being made absolute. 
Conditional order of divorce. A decree absolute is normally granted six weeks after the decree nisi, and from the date of the decree absolute the parties cease to be husband and wife. ...
A provisional order dissolving a marriage, which does not become final until a further application is made by the petitioner (at least six weeks after the decree nisi) and a decree absolute is granted.
[n] - a decree issued on a first petition for divorce
Order for divorce unless cause to contrary is shown within a set period
noun a decree issued on a first petition for divorce; becomes absolute at some later date
a decree, esp. of divorce, that will become absolute at a later date.