"I so apologize ... and this is sincere," he said, after taking a few deep breaths, on Tuesday's Tonight Show With Jay Leno. "I am a comedian, and you guys know that whatever I say, I don't mean any of it."
The audience laughed, but Foxx continued, "And sometimes, as comedians, as we do, we go a little bit too far."
On his Foxxhole show Sunday, Foxx -- who has a teenage daughter -- cracked that Cyrus, 16, needs "to get a gum transplant ... make a sex tape ... do some heroin." His other insults were too vulgar to reprint.
Explained Foxx, "I have a radio show... We're really the black Howard Stern. We go at everybody. There was a situation with Miley Cyrus, and I just want to say, I apologize for what I said. I didn't mean it maliciously. You know I'm a comedian. You know my heart."
Looking into the camera, he added, "Miley, I apologize, so I'll call you. I got a daughter too, so I completely understand."