Other forms: hairpins
A hairpin is a thin bent wire that holds hair up. Slide in a hairpin, lose a hairpin, a box of hairpins.
The U shape is what grips, and the ordinary hairpin has not changed in design for a very long time. A hairpin bend is a road turning back on itself through nearly 180 degrees, named for the shape, and mountain roads are full of them. Note bobby pin, which is the American term for the flat sprung kind; and that hairpins are proverbially the thing always lost.
1nounhairpinA thin bent wire that holds hair up.
“She pushed a hairpin into her bun to stop it falling down.”
2adjectiveturningTurning back sharply, of a bend.
“The road down the mountain has a series of hairpin bends.”
hairpin is a hair fastening.
Hair plus pin, first recorded in 1788 as two words. The hairpin bend was named from the shape in 1906, which is when the roads that needed it were being built.
From hair + pin, 1788 (as hair pin). Adjective sense 1906 in hairpin turn etc.
Etymology from Wiktionary, CC BY-SA
Practised in Hair & Grooming, Cycling