In the 18-minute video "Shady Cxvpher," Eminem is also joined by rappers Slaughterhouse and Yelawolf as they freestyle — rapping with no musical accompaniment.
in one of the lyrics, Eminem says, "I may fight for gay rights, especially if they dyke is more of a knockout than Janay Rice."
Janay Rice is the wife of Ray Rice, who was suspended indefinitely by the NFL following the release of a video that showed him knocking her out with a punch in an elevator at an Atlantic City hotel last February.
Eminem goes on to rap, "Play nice, bitch. I'll punch Lana Del Rey right in the face twice like Ray Rice in broad daylight, in plain sight of elevator surveillance, 'til the head is bangin' on the railin', then celebrate with the Ravens."
Del Rey praised Eminem in a 2012 interview, saying that "he's a genius" who "really changed my life."
"I didn't know music could be intelligent," she said. "He wasn't just rhyming for rhyme's sake. That made me think I could actually talk about the way things actually were. He's a genius."
So far, Del Rey has not responded to the song.
Eminem is scheduled to be in in Washington, D.C., tonight, performing with Bruce Springsteen, Rihanna and Metallica for a free concert to raise awareness for issues affecting veterans.