It has become the most searched-for word on a US dictionary site this week. From Trump’s dealings with Russia to May’s handling of Brexit – is it really right to call everything you disagree with treasonous?

‘If it prosper,” wrote the Elizabethan courtier John Harington, “none dare call it treason.” They dare now. After Donald Trump cooed that “President Putin was extremely strong and powerful in his denial” that Russia had interfered in his election, the cry of “treason” went up among Republicans and Democrats, and the word became the most-searched-for on the website of US dictionary Merriam-Webster.

According to the Oxford English Dictionary, treason (or “high treason”) means “violation by a subject of his allegiance to his sovereign or to the state”. It remains to be seen whether Trump’s alleged treason will be proved legally, but few in our febrile times can await such verdicts. In an era when everyone feels betrayed by something, crying treason is all the rage.

Brexit, too, has fuelled a surge in treason talk. In October 2017, the radio presenter Julia Hartley-Brewer said that Philip Hammond should be “tried for treason”. The letters editor of the Daily Telegraph last week asked: “Is Theresa May guilty of treason? Plenty of our readers seem to think so.” The lesson drawn was that “politicians would be wise to listen up”, rather than that plenty of that paper’s readers are mad.

According to the Treason Felony Act 1848, it remains treasonous to call for the abolition of the monarchy. Proscribed acts are treasonous not only if you do them, but also if you “compass, imagine, invent, devise, or intend” them. It is treason, too, to start or “imagine” starting an armed uprising “in order to intimidate or overawe both Houses or either House of Parliament”. So, if the former Trump adviser Steve Bannon were a British citizen, he might well be guilty of treason for saying on the radio that Middle Englanders should “rise up and make sure the guys in parliament [know] it” and “fight for your country”, adding: “This is war.”

As George Orwell said of the term “fascist”, if you call everything you disagree with “treason” then the word loses all power and specificity. That would help only the treasonous.