Health secretary Matt Hancock was forced to resign after he was shown on leaked CCTV footage attempting an oral swab of his adviser Gina Coladangelo. But he was not the first to get into trouble over an assistant, or, as the tabloidese has it, a “trusted aide”. The word “aide” comes straightforwardly from the French aider, to help, via the formal position of aide-de-camp, a senior officer’s assistant in the army’s “camp” or headquarters. In early English use, from the 18th century, the word was employed in a military context, with some allowances for culinary brigades (a head cook’s “aide” would be his sous-chef).

Our modern political sense emerges in the 19th century, first recorded in James Fenimore Cooper’s memoir Recollections of Europe (1837), where he describes Napoleon’s ruling style: “It was the policy of Napoleon to create a system of centralisation, that should cause everything to emanate from himself ... The prefects are no more than so many political aides, whose duty it is to carry into effect the orders that emanate from the great head.” On this analogy Hancock himself, who remains an MP, is but an aide to the prime minister, however irresistible his own great head might be.

• Steven Poole’s A Word for Every Day of the Year is published by Quercus.