whale tail
n.— «Another distraction occurs when pants ride low in the back and expose thong underwear, a phenomenon students have dubbed “whales’ tails.” “If you a 16-year-old boy in an English class, and you’ve got three whales’ tails in front of you, it’s pretty hard to concentrate on verbs,”» —“Updated Dress Code Addresses New Styles” by Tom Quinn Oregonian (Portland) June 24, 2004. (source: Double-Tongued Dictionary)
Further reading
Amid court-ordered busing in the 1970s, a middle-school teacher tried to distract her nervous students on the first day of class with this strange assignment: find a monarch caterpillar. The result? A memorable lesson in the miracle of metamorphosis...
There was a time when William Shakespeare was just another little seven-year-old in school. Classes in his day were demanding — and all in Latin. A new book argues that this rigorous curriculum actually nurtured the creativity that later flourished...