An unusually long hair follicle. Often found in unusual parts of ones body where other hairs are not found. If it is with other hairs it is found growing in the opposite direction. Thoink sizes can vary from 2 to 3 inches.
"Gee Mike, take a look at that thoink on your back"
"Ian come over here and let me pluck that thoink, I can't bare to look at it any longer!"