John Kelly, the White House Chief of Staff, has a way with words. During the invasion of Iraq in 2003 he was asked if the Marine Corps forces he led might be defeated by the strong Iraqi army defending Baghdad. ‘Hell these are Marines,’ he said. ‘Men like them held Guadalcanal and took Iwo Jima. Baghdad ain’t shit.’

Now he must cope with Donald Trump. At the end of last month it was reported, from an anonymous source, that he had remarked that the President was ‘becoming unhinged’. Before midnight that day, Mr Trump tweeted that ‘the Fake News is going crazy’ and ‘are totally unhinged’. Eleven minutes later, another tweet from him said: ‘Fake News is going “bonkers”!’

My husband said he thought bonkers was a Royal Navy word. Eric Partridge, that patient collector of slang, agreed, seeing it as derivative from bonk, ‘to hit’ (especially on the head). Bonkers in the 1920s could mean ‘mildly drunk’, and Jonathon Green notes in Green’s Dictionary of Slang that in the first world war bonk was a verb for ‘shell’.

It is no coincidence that bonk developed the meaning ‘have sexual intercourse’. ‘She has been bonking the chairman of the neighbouring constituency’s Conservative association,’ said the Daily Telegraph in an opinion piece in 1986. It was a word that delighted Peregrine Worsthorne, briefly editor of the Sunday Telegraph, because its non-taboo status allowed wider discussion of sexual intercourse. In 1973, his use on television of the taboo word fuck had, he surmised, cost him the editorship of the Daily Telegraph, annoying the proprietor, Lord Hartwell.

The Oxford English Dictionary agrees with Partridge that fuck shares descent with the Latin pugnare. Bonk joined other words meaning ‘hit’ (bang, poke) in the sexual sense. Yet bonkers, people who bonk, are seldom confused with people who are bonkers.

Bonkers is often associated with Mr Trump in the US press. He is not alone. Bonkers D. Bobcat featured in his own cartoon show Bonkers on the Disney Channel in the 1990s. As the name suggests, he was a bobcat. Failing in showbusiness, he became a cop. From beneath his uniform cap, an unruly great quiff of orange hair stuck out.