- A legal treatise which lays down principles or collects decisions on any branch of the law. THANAGE OF THE KING.-A certain part of the king's land or property, of which the ruler or governor was called "thane." Cowell. THANE.-An Anglo-Saxon nobleman; an old title of honor, perhaps equivalent to baron. There were two orders of thanes, the king's thanes and the ordinary thanes. Soon after the Conquest this name was disused.-Cowell.