Pronunciation: (hâr'pin"), [key]
a slender U-shaped piece of wire, shell, etc., used by women to fasten up the hair or hold a headdress.
(of a road, curve in a road, etc.) sharply curved back, as in a Ushape: a hairpin turn.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.