“Cooked.” “Low-key.” “Sus.” And now, the cryptic “6-7.” In her recent article, “What Does ‘6-7’ Mean? Maybe Tweens Don’t Want You to Know,” Callie Holtermann explores the latest slang trends baffling adults and taking over classrooms. She highlights the phenomenon of “6-7,” a phrase as ubiquitous as it is meaningless. “‘Six-seven’ feels a bit like a nonsense grenade,” Ms. Holtermann writes. She asks if today’s slang is simply “brain rot” or rather a “gleeful obfuscation” designed to keep older generations in the dark. We asked students to weigh in. Is “6-7” actually funny? Is it annoying? And what does it...