Fergie's name for her son came to her in a dream.
The 'London Bridge' singer and husband Josh Duhamel welcomed their first son, Axl, into the world three months ago and the pop star says his unusual name came to her as she was dreaming about rocking out.
She told talk show host Ellen DeGeneres: "I had this dream and I was in the audience at this festival. It was outdoors and it was all grimy and nobody knew who I was.
"On stage singing was Jim Morrison and then came Bob Marley and then Axl Rose. I was in heaven in this dream and I'm dancing and just getting into the music."
Fergie - full name Stacy Ferguson - claims her baby son seemed to be enjoying the dream concert in the womb.
She explained: "It was the first time my son kicked me in the stomach and it was like he was feeling the music with me. It was really beautiful and I woke Josh up and I said, 'Honey, honey, honey, he kicked me. He finally kicked me.' "
Fergie and Josh gave their son the middle name of Jack and they had decided on that moniker because they wanted to honour the 38-year-old singer's late uncle.
And the couple were thrilled when they realised it went perfectly with Axl.
The Black Eyed Peas star said: "I told the story and he was like, 'Morrison? Marley? No. Axl Jack. That's it!' It just had this ring to it. It was very strong."