The Duke and Duchess of Sussex rejected the title Earl of Dumbarton for their son Archie because it contained the word "dumb", it has emerged.

Multiple sources have told The Telegraph that both Harry and Meghan declined to use the title of Scottish nobility because they feared Archie might be bullied or attract unfortunate nicknames.

The word dumb is more prevalent in the US, where is it frequently used as slang for stupid.

A source said: “They didn’t like the idea of Archie being called the Earl of Dumbarton because it began with the word ‘dumb’ [and] they were worried about how that might look.”

Another insider added: “It wasn’t just Meghan who pointed out the potential pitfalls, it also bothered Harry.”

The Duke and Duchess of Sussex holding Archie during a meeting with Archbishop Desmond Tutu on a tour of South Africa

Credit: Toby Melville/PA Wire

The revelation follows reports that relations between the couple and Prince Charles plunged to an all time low after he told them Archie will never become a prince because he wants a slimmed-down monarchy when he becomes king.

According to sources close to the Sussexes, the heir to the throne allegedly told them he plans to change key legal documents to ensure that his great-grandson cannot get the title he would once have inherited by right.

Yet the claims have left royal watchers baffled after several sources confirmed to The Telegraph that Harry and Meghan “never raised an issue” about Archie not being a prince until they gave an interview to Oprah Winfrey in March.

Harry was said to be “adamant” that Archie, now two, "should be raised without titles like his cousins Peter and Zara Philips".

Another insider confirmed: “The couple didn’t want any titles for their children,” although suggested Harry “feared” that when his father took the throne, he would change the George V convention specifying that the grandchildren of a monarch automatically become a prince or princess.

During their bombshell interview with the US chat show host, the Duchess hinted Archie had been blocked from a royal title and therefore a His Royal Highness prefix, which meant he would no longer receive taxpayer funded security.

She said: "They didn’t want him to be a prince or princess, not knowing what the gender would be, which would be different from protocol, and (said) that he wasn’t going to receive security.

She added: “In those months when I was pregnant we have in tandem the conversation of, you won’t be given security, not gonna be given a title and also concerns and conversations about how dark his skin might be when he’s born."

Insisting she did not care about "all the grandeur surrounding this stuff", the Duchess declared: “The most important title I’ll ever have is mom.”

Dumbarton: a brief history

The Earl of Dunbarton title was first created in the Peerage of Scotland in March 1675 for Lord George Douglas, son of the Marquess of Douglas and younger brother of the Earl of Selkirk, for services fighting in the Franco-Dutch War.

Lord Dumbarton was also created Lord Douglas of Ettrick. He was married to Anne Douglas, the first Countess of Dumbarton, who was the sister of Catherine Fitzroy, Duchess of Northumberland. 

Following the death of their only son, the unmarried second Earl, both titles became extinct in January 1749.

The title was recreated in the UK Peerage by the Queen as one of the two subsidiary titles for her grandson Harry, when he married Meghan in May 2018. 

He was also created Baron Kilkeel. His son is the heir to the earldom but when he was born in May 2019, the couple insisted that he would simply be known as Archie Mountbatten-Windsor.

A spokeswoman for the Sussexes declined to comment.