Eschéat. n.s. [from the French eschevir.] Any lands, or other profits, that fall to a lord within his manor by forfeiture, or the death of his tenant, dying without heir general or especial. Escheat is also used sometimes for the place in which the king, or other lord, has escheats of his tenants. Thirdly, escheat is used for a writ, which lies where the tenant, having estate of fee-simple in any lands or tenements holden of a superiour lord, dies seised, without any heir general or especial; for, in this case, the lord brings this writ against him that possesses the lands after the death of his tenant, and shall thereby recover them. Cowel.
If the king's ordinary courts of justice do not extend to protect the people, if he have no certain revenue or escheats, I cannot justly say that such a country is wholly conquered. Davies on Ireland.