The word expropriation is synonymous with "eminent domain" and is used in certain countries as jurisdictions, some of which do not pay compensation for the confiscated property.
The exercise of eminent domain is not limited merely to real estate. Governments may also comdemn the value in a contract such as a franchise agreement (which is why many franchise agreements will stipulate that in condemnation proceedings, the franchise itself has no value).
In the United States, the Fifth amendment requires that just compensation be paid when the power of eminent domain is used.
In France, the Declaration of the Rights of Man and of the Citizen similarly mandates just and preliminary compensation before expropriation.