also hair-pin, 1788 (two words), from hair + pin (n.). A hairpin turn, etc., is from 1906. Hairpin (or clothespin) was American English slang for "person" c. 1880-1910, especially in the expression "That's the kind of hairpin I am."
1. The road is a succession of hairpin bends, hills, and blind corners.
2. The roads twist round hairpin bends.
3. There are eighteen hairpin bends on the way up Mogan Mountain.
4. I executed the hairpin turn high on the sheer western face of the mountains.
5. Hairpin turns force the car to crawl at 10 miles an hour in some places.