A decree is an official order given by a government or by a person with power. For example, the president can issue a decree making a particular day a national holiday. It has the force of law.
It can also be defined as an order handed down by a judge that resolves the issues in a court case. For example, marriages can be dissolved by judicial decree.
In Nigeria, military rules the people through decrees and edicts. Laws passed by the central government during military regimes are known as decrees while those passed by regional governments during military regimes are known as edicts.