Definition of Lord Warden in US English:

Lord Warden

noun

historical
  • (The title) of a governor of a province or district, especially the Marches; compare "Warden of the Marches". Often in Lord Warden of the Cinque Ports and Lord Warden of the Stannaries.

Origin

Late 16th century; earliest use found in George Abbot (1562–1633), archbishop of Canterbury.