The meaning behind Elon Musk and Grimes’ children’s names, X AE A-XII and Y

The former couple have explained what the names mean and how to pronounce them

While Elon Musk and Grimes are no longer romantically involved, the former couple share two children with rather unusual names.

The Tesla CEO, 52, and the 35-year-old Canadian singer, whose real name is Claire Elise Boucher, began dating in 2018. They had an on-again, off-again relationship over the next four years, but ultimately ended things in March 2022.

When they welcomed their first child in May 2020, the couples made headlines for giving their son a very unique name, X Æ A-12 Musk.

However, both parents appeared to have different pronunciations for the name. Explaining the meaning behind each part of the name, Grimes tweeted that the “X” symbolised “the unknown variable”, while “Æ” was the “elven spelling of AI (love and/or artificial intelligence”.

The last part of the name, “A-12”, was a nod to the precursor to her and Musk’s “favourite aircraft”, the SR-71, a strategic reconnaissance aircraft built by American aerospace company Lockheed.

In an Instagram Q&A, Grimes explained how to pronounce her son’s name and wrote: “It’s just X, like the letter X. Then AI. Like how you said the letter A then I.”

However, Musk’s own pronunciation of the name differs from Grimes’. In an interview with Joe Rogan for his podcast, the South African billionaire said: “I mean, it’s just X, the letter X. Um, and then, the Æ is, like, pronounced ‘Ash’. And then A-12, A-12 is my contribution.”

In 2022, the couple welcomed a daughter via surrogate, but kept her birth a secret until Grimes appeared to accidentally reveal the child during an interview with Vanity Fair.

The singer had invited writer Devin Gordon into her home in Austin, Texas. When Gordon heard a baby cry, they asked Grimes if she had another child apart from X.

She replied by saying she was “not at liberty to speak on these things”, but later admitted that they had indeed welcomed a baby girl, who was named Exa Dark Sideræl Musk.

Each part of the name “Exa Dark Sideræl Musk” also carried different meanings, according to Vanity Fair. Exa refers to the supercomputing term exaFLOPS, while Dark symbolises “the unknown”.

Grimes said: “People fear it but truly it’s the absence of photons. Dark matter is the beautiful mystery of our universe.”

“Sideræl”, which she pronounced “sigh-deer-ee-el” is a “more elven” spelling of sidereal, the “true time of the universe, star time, deep space time, not our relative earth time”.

Grimes also said that the name choice is a reference to her favourite character from Lord of the Rings, Galadriel.

Since both children were born, their parents have changed their names for different reasons.

Recently, Grimes and Musk had to change their son’s name to comply with Californian law. Under the law, names must be written on birth certificates using the 26 alphabetical letters of the English language. It does allow for apostrophes and dashes.

According to TMZ, the baby’s name that was officially confirmed on his birth certificate differs slightly from the name the couple originally gave him. It states the baby’s first name is “X”, the middle name is “AE A-XII”, and last name is “Musk”.

Musk has previously spoken about his preoccupation with the letter “X”, having recently rebranded Twitter as X, less than a year after he acquired the social media platform for US$44bn. The shake-up saw Twitter’s icon changing from the recognisable blue bird logo to a black-and-white X logo.

This week, Musk had a large “X” logo installed on top of the Twitter headquarters, which shines and flashes brightly at the buildings directly opposite. San Francisco’s Department of Building Inspection said it is investigating the signage after a series of complaints, as it may violate permitting rules.

(REUTERS/Carlos Barria)

The SpaceX founder tweeted following the rebrand: “I like the letter X. X will become the most valuable brand on Earth. X? Can you imagine Musk picking J for the job? Or H? There would be puzzlement, as there is now, and not much else. But X also creates a certain frisson. Why?”

Earlier this year, in March, Grimes revealed she shortened her daughter’s unusual name.

She shared two photographs on the social media platform formerly known as Twitter, showing her daughter and herself in matching red onesies and green hair. In the caption, the singer wrote: “Y [dragon emoji] C.”

In a follow-up tweet, Grimes later confirmed that her daughter’s name had been changed and she would go by just “Y”.

“She’s Y now, or ‘Why?’ or just ‘?’ (But the government won’t recognise that,” she wrote, adding: “The scuriosity [sic], the eternal question, … and such.”