black rod

noun

1. (in England) an official of the Order of the Garter and chief ceremonial usher of the House of Lords: so called from the rod carried as the symbol of office.
2. a similar official in British colonial and Commonwealth legislatures.

noun

1. (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