A hairpin is a small piece of metal or plastic bent back on itself which someone uses to hold their hair in position. A hairpin is the same as a hairpin bend. A hairpin or hair pin is a long device used to hold a person’s hair in place. It may be used simply to secure long hair out of the way for convenience or as part of an elaborate hairstyle or coiffure. Most hairpins share this narrow, bent shape, and it’s from this sharp angle that the term “hairpin turn” gets its name. A bend in a road that doubles back in a tight curve is a hairpin turn or a hairpin bend. Hair accessories are functional or ornamental objects wrapped, tied, twisted, inserted, or otherwise attached to the hair. Throughout history, types of ornamentation and the materials from which they were made indicated religious significance, social class, age group, and level of fashion awareness. Highways with repeating hairpin turns allow easier, safer ascents and descents of mountainous terrain than a direct, steep climb and descent, at the price of greater distances of travel and usually lower speed limits, due to the sharpness of the turn.The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions, base-pair to form a double helix that ends in an unpaired loop. a thin thread of something, often one of a few, twisted around each other to make a string … the mass of thin thread-like structures on the head of a person, or any of these structures that grow out of the skin of a person.