chignon (n.)

"knot or coil of hair worn at the back of the neck," 1783, from French chignon "nape of the neck," from Old French chaignon "iron collar, shackles, noose" (12c.), from Vulgar Latin *catenionem (nominative *catenio), from Latin catena "chain, fetter, restraint" (see chain (n.)). Popular 1780s, 1870s, 1940s. Form influenced in French by tignon "coil of hair."