The Collaborative International Dictionary
Majorat \Ma`jo`rat"\, n. [F. majorat, LL. majoratus. See Major, a., and cf. Majorate.]
The right of succession to property according to age; -- so termed in some of the countries of continental Europe.
(French Law) Property, landed or funded, so attached to a title of honor as to descend with it.
Wiktionary
n. (context legal English) property that descends with a title
Wikipedia
Majorat is a French term for an arrangement giving the right of succession to a specific parcel of property associated with a title of nobility to a single heir, based on male primogeniture. A majorat ( fideicommis) would be inherited by the oldest son, or if there was no son, the nearest relative. This law existed in some European countries and was designed to prevent the distribution of wealthy estates between many members of the family, thus weakening their position. Majorats were one of the factors easing the evolution of aristocracy. The term is not used of English inheritances, where the concept was actually the norm, in the form of entails or fee tails. Majorats were specifically regulated by French law. In France, it was a title of property, landed or funded, attached to a title instituted by Napoleon I and abolished 1848.
Often the title could not be inherited if the property did not pass to the same person. Like English entails, the implications of majorats were often used in fiction to furnish complexity in plots; Honoré de Balzac was especially interested in them.
In the Polish–Lithuanian Commonwealth, majorat was known as ordynacja and was introduced in late 16th century by king Stephen Báthory. A couple of Polish magnates' fortunes were based on ordynacja, namely those of the Radziwiłłs, Zamoyskis, Wielopolskis. was abolished by the communist agricultural reform in the People's Republic of Poland. Thus Communist Ruled Poland, from 1947 or 47 to 1989.
In Portugal it was called or and one of the requirements to inherit a morgado was to pass down the family name related to the morgado. Women with no brothers could inherit a morgado: in that case their children would inherit the mother's name. If the husband was also a morgado, the children would inherit both names. This led to a tradition of very long family names in the Portuguese nobility.
In Spain it was known as , and become a part of the Castilian law since 1505 until 1820. Basque majorats could be inherited by the oldest male or female child.