Elon Musk has revealed how to pronounce his and Grimes' baby son's name.

The couple recently welcomed X Æ A-12 into the world and after fans puzzled over the correct pronunciation, Elon revealed all.

Speaking on 'The Joe Rogan Experience' podcast, he explained: ''It's just the letter X and then the Æ is pronounced 'Ash. A-12 is my contribution.... Coolest plane ever. It's pretty great.''

He explained that Grimes ''mostly came up with the name,'' adding: ''Yeah, she's great at names.''

X Æ A-12 is Grimes' first child, while Musk has five children with his former wife Justine Wilson. The former couple also had son Nevada together but he died of sudden infant death syndrome at 10 weeks in 2002.

Elon, 48, revealed that he ''appreciates'' being an older dad and is besotted with little X Æ A-12.

He said: ''Actually I think it's better being older and having a kid. I appreciate it more. Babies are awesome. They're little lovebugs. Wonderful, it's great. Also, I've spent a lot of time on AI so you can kind of see the brain develop and you can see it learning very quickly.''

Meanwhile, Elon recently corrected Grimes' explanation of their son's name after she took to Twitter to explain its origins.

She wrote: ''X, the unknown variable ... Æ, my elven spelling of Ai (love &/or Artificial intelligence) ... A-12 = precursor to SR-17 (our favourite aircraft). No weapons, no defences, just speed. Great in battle, but non-violent + (A=Archangel, my favourite song) (metal rat) (sic).''

However, Musk couldn't help jumping into the comments to correct his partner.

He wrote: ''SR-71, but yes,'' in reference to the aircraft and it didn't take Grimes, 32, long to put him in his place.

She tweeted: ''I am recovering from surgery and barely alive so may my typos b forgiven but, damnit. That was meant to be profound (sic).''

Elon quickly backed down and wrote: ''You are a powerful [fairy emoji, queen emoji].''