A "hairpin" is a U-shaped metal or plastic accessory commonly used to hold hair in place. It is used to create a neat and secure hairstyle by sliding it into the hair, forming a loop or twist and holding it tightly. Full definition
There are many points in the races where you are turning hairpin turns with no walls between them. (brutalgamer.com)
After leaving the main highway, the final leg of the trip may be a rather bumpy ride as the road leads downwards in a series of hairpin bends on a largely unfinished surface. (beautifulworld.com)
But in the end, I'm so happy with how my new reclaimed barn wood console table with hairpin legs turned out. (sustainmycrafthabit.com)