aide-de-camp:
(a French word for a ‘camp assistant’; short form: ADC; plural: ‘aides-de-camp’ or ‘aids-de-camp’)
aide-de-camp (standing)
a military officer who accompanies/stays with and helps an officer of higher rank in his/her duties or who accompanies government dignitaries, such as a governor, president, etc.;
an assist; an adjutant; a secretary,
an Arab dignitary with his aide-de-camp in military uniform (R)
As the tradition goes in Britain, the Queen’s personal aide-de-camp is her own son, the Prince of Wales, Prince Charles! Most political dignitaries have aides-de-camp following them wherever they go in public just to maintain certain dignity and status.
