whale tail
n.β Β«Another distraction occurs when pants ride low in the back and expose thong underwear, a phenomenon students have dubbed “whalesβ tails.” “If you a 16-year-old boy in an English class, and youβve got three whalesβ tails in front of you, itβs pretty hard to concentrate on verbs,”Β» ββUpdated Dress Code Addresses New Styles” by Tom Quinn Oregonian (Portland) June 24, 2004. (source: Double-Tongued Dictionary)