QT stands for "quiet tip" ya schmucks. (Though the other
definition is almost correct, since "tip" refers to the tip of a tongue)
This phrase spawned "on the bomb tip" by rappers, to mean the opposite of keeping quiet; rather,
something "
poppin" or "off the hook." This phrase is also a play on the phrase "bomb tip" in the sense of a tip to the police about a bomb (which would understandably cause a wild scene or commotion)
"I'm tryna
keep this party on the qt, man"
"Fuck that
noise, homeboy, this shit gon' be off
the hook"