While the baby name announcement sent Twitter into a frenzy as fans tried to figure out if Musk was joking and, if not, how the baby's name is pronounced, Grimes stepped in to explain how they came up with the truly unique moniker in the first place.
Seemingly confirming that their child's name is in fact X Æ A-12, Grimes said each portion and character had a special significance.
According to Grimes, X stands for "the unknown variable," while Æ is "my elven spelling of Ai (love &/or Artificial intelligence), while the A-12 refers to an aircraft which is the "precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent."
She went on to explain that the A also refers to "Archangel, my favorite song."
•X, the unknown variable ⚔️ •Æ, my elven spelling of Ai (love &/or Artificial intelligence) •A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent 🤍 + (A=Archangel, my favorite song) (⚔️🐁 metal rat)
Musk then corrected her on the aircraft, writing: "SR-71, but yes."
She replied, "I am recovering from surgery and barely alive so may my typos b forgiven but, damnit. That was meant to be profound 🦔."
However, when it comes to how to actually pronounce the name, Grimes offered no suggestions. One fan suggested that the name could be pronounced "X Ash Archangel" -- as Æ is a typographical character referred to as ash.
Musk liked this particular tweet, leading many to think that could be a confirmation.
He also gushed over the mother of his newborn son, tweeting that Grimes was "powerful."
Musk announced the birth of his son on Monday, writing that "mom and baby all good" on Twitter. The news came just four hours after he said that Grimes, whose real name is Claire Boucher, was just "a few hours away" from giving birth.
The couple, who have been dating since 2018, first announced the pregnancy in January. While this is Grimes' first child, Musk shares five kids with his first wife, Canadian author Justine Wilson.