Source : Webster's Revised Unabridged Dictionary (1913)

Chignon \Chi"gnon\, n. [F., prop. equiv. to cha[^i]non link, fr.
   cha[^i]ne chain, fr. L. catena Cf. {Chain}.]
   A knot, boss, or mass of hair, natural or artificial, worn by
   a woman at the back of the head.

         A curl that had strayed from her chignon. --H. James.

Source : WordNet®

chignon
     n : a roll of hair worn at the nape of the neck