ˈlēshēˌōə̇ˈnȯrmə̇s noun
or laesio ultra di·mi·di·um -də̇ˈmidēəm ; or laesio ultra du·plum -ˈd(y)üpləm
Etymology: laesio enormis, Late Latin, literally, enormous injury; laesio ultra dimidium, Latin, injury over half; laesio ultra duplum, Latin, injury over double
Roman & civil law : the injury that is suffered by a vendor who has sold something for less than half its value or in some civil-law systems by a purchaser who has bought something at more than double its price and that in most cases gives the right of rescinding the sale