Exa Dark Sideræl Musk: What is the meaning behind Grimes and Elon Musk’s baby name?

Couple welcomed second child via surrogate in December

What is the meaning of Grimes and Elon Musk’s baby name? (AFP via Getty Images)

Grimes and Elon Musk have grown their family with the arrival of a daughter named Y, whose full name is Exa Dark Sideræl Musk.

The singer, 33, whose real name is Claire Elise Boucher, shared the news that she and the Tesla founder welcomed a baby via surrogate in December in a new cover story for Vanity Fair.

After first playing off the sounds of a crying infant, Grimes, who also shares son X with Musk, said: “I’m not at liberty to speak on these things. Whatever is going on with family stuff, I just feel like kids need to stay out of it, and X is just out there.”

However, she then confirmed that she and Musk, who she referred to as her boyfriend, had welcomed a daughter.

While the journalist noted that they didn’t feel comfortable asking the singer for the baby’s full name, Grimes later revealed in a text that her daughter’s name is Exa Dark Sideræl Musk, as well as the meaning behind the unique name.

“It’s fire,” she wrote via text, before adding: “Her full name is Exa Dark Sideræl Musk.”

According to Vanity Fair, Exa refers to the supercomputing term exaFLOPS, while Dark refers to “the unknown”. “People fear it but truly it’s the absence of photons. Dark matter is the beautiful mystery of our universe,” Grimes explained.

Sideræl, which Grimes 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,” the singer added.

According to Grimes, the name choice is also a reference to her favourite Lord of the Rings character, Galadriel, who she noted “chooses to abdicate the ring”.

While the name is as unique as the couple’s son’s name, whose full name is  X Æ A-12, Grimes revealed that she may end up changing her daughter’s name, as she and Musk already occasionally call her Sailor Mars, a nickname inspired by the Sailor Moon manga series.

She also admitted that she is concerned the baby’s name may be “boring,” according to the outlet, with Grimes explaining that she had pushed for her and Musk’s daughter to be named Odysseus Musk, but that they had ultimately compromised.

“A girl named Odysseus is my dream,” she said.

Grimes previously revealed the meaning behind the couple’s son’s name, who they call X AI Archangel or X, on Twitter shortly after his birth in May 2020.

At the time, the singer explained that the name includes references to her and Musk’s favourite aircraft, SR-17, and the elven spelling of AI, while the X is a reference to the unknown variable commonly used in mathematical sums.