(in Britain) an officer of the House of Lords and of the Order of the Garter, whose main duty is summoning the Commons at the opening and proroguing of Parliament
2.
a similar officer in any of certain other legislatures
Black Rod in American English
1.
in England, the chief usher to the Order of the Garter and the House of Lords
so called from his symbol of office, an ebony rod: in full, Gentleman Usher of the Black Rod
2.
a similar official in other Commonwealth parliaments