escheat

n. forfeiture of assets, requisition of property

Escheat is a common law doctrine that operates to ensure that property is not left in limbo and ownerless. It originally referred to a number of situations where a legal interest in land was destroyed by operation of law, so that the ownership of the land reverted to the immediately superior feudal lord.
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(v. t.)
To forfeit.
  

(v. i.)
To revert, or become forfeited, to the lord, the crown, or the State, as lands by the failure of persons entitled to hold the same, or by forfeiture.
  

(n.)
The reverting of real property to the State, as original and ultimate proprietor, by reason of a failure of persons legally entitled to hold the same.
  

(n.)
The falling back or reversion of lands, by some casualty or accident, to the lord of the fee, in consequence of the extinction of the blood of the tenant, which may happen by his dying without heirs, and formerly might happen by corruption of blood, that is, by reason of a felony or attainder.
  

(n.)
That which falls to one; a reversion or return
  

(n.)
Lands which fall to the lord or the State by escheat.
  

(n.)
A writ, now abolished, to recover escheats from the person in possession.
  

The result of an incident that causes a fief to revert because a lord or tenant dies without an appropriate heir whose qualifications are generally noted in the original grant.

Where property is returned to the government upon the death of the owner, because there is nobody to inherit the property - (read more on Escheat)