Meaning of Lord Mayor's day in English:

Lord Mayor's day

noun

  • The day on which the new Lord Mayor of the City of London goes in ceremonial procession to the Royal Courts of Justice (formerly to Westminster), to be presented to the Lord Chief Justice and swear allegiance to the monarch.

    Lord Mayor's day dates back to 1215. It used to be November 9, but since 1959 it has always been the second Saturday in November. The ceremonial procession developed into the Lord Mayor's Show.

Origin

Late 16th century; earliest use found in Robert Greene (bap. 1558, d. 1592), writer and playwright.