Musk announced the birth of their baby boy in a post on Twitter Tuesday, telling a fan that they had chosen to call him X Æ A-12 Musk.
Memes around the choice of moniker came thick and fast with many members of the online community wondering how it was pronounced.
Grimes has since broken down each character of their son's name in a Twitter post.
The Canadian musician -- real name Claire Elise Boucher -- explained "X" stands for "the unknown variable."
Meanwhile, "Æ" is the Elven spelling of AI, which is shorthand for artificial intelligence and translates to "love" in several languages, such as Japanese.
The 32-year-old star then shared that a part of her son's name is a reference to the couple's favorite aircraft.
"A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent," she added.
Grimes concluded the message by revealing that the "A" in the name also represents "Archangel," which she described as her favorite song.
While she was kind enough to decipher the name, she did not inform fans how to actually pronounce it.
X Æ A-12 is the couple's first child together. Musk, 48, has five other children -- twins Griffin and Xavier and triplets Damian, Saxon, and Kai -- from a previous marriage.
Grimes confirmed her pregnancy in January when she posted on Instagram describing the difficulties of being pregnant while working.
"I feel like I was woefully ill prepared [because] I [don't know] if pregnancy is as visible or discussed as it should be," she wrote.
“I just didn’t [really] understand what I was getting into. It’s been good too, but it makes working a lot harder. Good at writing and having lots of wild ideas [though], but anything physical is hard. I’m also way more emo and less capable of bravery in the face of haters online and stuff haha.”