Fee tail
Fee tail or entail is a legal concept and set of associated rules restricting the manner in which real property (especially land) passes from one generation to the next; these rules tend to keep deceased estates together as a whole, and in the hands of a single owner (heir), rather than allowing them to be split up amongst multiple children (as would tend to happen in similar situations in Continental European law). Entail has been known in English law since feudal times, and it has evolved as the law has evolved.