2.A mispronunciation to the wordworld,that happens to be used by some songwriters to make it rhyme with the word girl.Not necessarily trashy artists have used it.
1.She saw a mass of bodies whirling round on the dance floor
A severely idiotic, toxic person who is hated by almost everyone that knows them due to their assholishness and immaturity. They are also incapable of fixing themselves and will make up excuses like "I'm disabled" or "I'm only age", so don't even bother trying to talk sense into them. Whirls are not to be trusted, as they could leak secrets you trusted them to keep or raid your Discord server out of sheer boredom.
Person: Grow the fuck up.
Whirl: NOOOOO!!!!! LET ME DO WHAT I WANT!
Person: Ok then, have fun being a whirl.