Prince Charles has a secret codename for his youngest daughter-in-law Meghan Markle, and it's actually a huge compliment for the former American actress.

Royal commentator Christine-Marie Liwag Dixon told viewers on "The List" that Meghan hasn't had an easy time since she joined the British royal family after her marriage to Prince Harry in May 2018, reports Birmingham Live.

"Not only has the press hounded her relentless [sic], but she has also said that she felt less than at home in the Royal Family. The Royal Family may not have approved of Meghan and Harry stepping down as senior royals despite them doing so to escape an environment that was clearly not good for their mental health," Dixon said, referring to the revelations made by the Sussexes in their interview with Oprah Winfrey in March.

In the tell-all, Harry had also said that his father had stopped taking his calls following two conversations about him wanting to quit as a working royal. However, Dixon says that the Prince of Wales, who walked Meghan down the aisle at her wedding to his son, seemingly "had a lot of respect for her resilient nature."

"This was evident in the secret nickname he reportedly had for her: 'Tungsten'. As royal correspondent Russell Myers revealed on Lorraine in 2019, Charles nicknamed her after the metal as 'she is tough and unbending,'" Dixon said.

She further noted that Tungsten is the strongest naturally occurring metal on the planet so that makes Charles's moniker for Meghan "a pretty neat compliment all things considered."

Prince Charles and Meghan haven't met since she paid a short visit to the UK in March last year to finish off a final round of engagements as a working royal. Though Meghan didn't say much about her father-in-law in her Oprah interview, Harry went all out against him in the tell-all as well as his subsequent interviews.

In the tell-all, Harry said he feels "disappointed" and "let down" by his father for not supporting him even though he was facing the same troubles the heir apparent previously struggled with. In his Apple TV+ mental health series "The Me You Can't See" with Winfrey released last month, the Duke of Sussex further criticised his father's parenting and reiterated that Charles is letting his sons suffer just because he suffered himself.

"My father used to say to me when I was younger, he used to say to [Prince] William and I, 'Well, it was like that for me, so it's gonna be like that for you.' That doesn't make sense. Just because you suffered, it doesn't mean that your kids have to suffer. In fact, quite the opposite," Harry said, adding that he will be "breaking the cycle" with his own children.

Harry and Meghan are parents to a two-year-old son Archie and are expecting to welcome a baby girl in the coming weeks. The newborn will be the fifth grandchild and second granddaughter of Prince Charles.

The British royals
The British royals Photo: AFP / Paul ELLIS