"'Swish Swish'—is that about anybody we know?" he asked, referring to her new song with Nicki Minaj.
Many people have speculated the track about Taylor Swift , with whom the pop star is reportedly feuding. Swift has not commented about the song, although Orange Is the New Black star Ruby Rose, a member of her "squad" of pals, dragged Perry over it.
"I think it's a great anthem for people to use whenever somebody's trying to hold you down or bully you," the singer told Fallon, raising her eyebrows.
"That's kinda what this record is about, it's just like 360-degree liberation," she said, referring to her upcoming fifth studio album Witness. "[First single] "Chained to the Rhythm" was this political liberation, [second single] "Bon Appétit" was a sexual liberation and now, I think this is kind of, 'Swish' represents the liberation from all the negative that doesn't serve you."
Many people think Swift's 2014 revenge anthem "Bad Blood" is about Perry. Swift told Rolling Stone that year that the track is about a female artist, who she did not name.
"For years, I was never sure if we were friends or not," she said. "She would come up to me at awards shows and say something and walk away, and I would think, 'Are we friends, or did she just give me the harshest insult of my life?'"
Swift also told Rolling Stone that in 2013, the other singer "did something so horrible."
"I was like, 'Oh, we're just straight-up enemies,'" she said. "And it wasn't even about a guy! It had to do with business. She basically tried to sabotage an entire arena tour. She tried to hire a bunch of people out from under me. And I'm surprisingly non-confrontational—you would not believe how much I hate conflict. So now I have to avoid her. It's awkward, and I don't like it."
A day after the article was published, Perry tweeted, "Watch out for the Regina George in sheep's clothing..."
Minaj has not commented on the meaning behind "Swish Swish."
"If your video celebrates women with very slim bodies, you will be nominated for vid of the year," she said.
Taylor was nominated in the category for, yes, "Bad Blood." The video featured several members of her squad, including Victoria's Secret models. She took Minaj's tweet personally.
"I've done nothing but love & support you," she tweeted at her. "It's unlike you to pit women against each other. Maybe one of the men took your slot.."
Minaj responded and she had never said a word about her, adding, "I love u just as much. But u should speak on this."
Perry weighed in, tweeting, "Finding it ironic to parade the pit women against other women argument about as one unmeasurably capitalizes on the take down of a woman..."